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FOUNDRY  PRACTICE 


A  Text   Book   for   Molders 
Students   and  Apprentices 


BY 
R.  H.  PALMER 

Molder,  Foreman  and   Superintendent  of   Foundries  ;    Sometime   Instructor 

in   Foundry   Practice   at  the   Worcester   Polytechnic 

Institute,  Worcester,  Mass. 


FIRST   EDITION 
FIRST  THOUSAND 


NEW    YORK 

JOHN    WILEY   &   SONS 
LONDON  :    CHAPMAN   &   HALL,    LIMITED 

1912 


MAY  3       19if 


COPYRIGHT   1911 
By  R.   H.   PALMER 


I  OF  THE  PUBLISHERS  PRINTING  COMPANY,  NEW  YORK,  U.  8.  A. 


3 

0 


PREFACE 

DURING  his  experience  as  instructor  in  foundry  practice 
at  the  Worcester  Polytechnic  Institute,  the  author  was 
handicapped  by  the  lack  of  a  suitable  text-book.  The  vol- 
ume presented  here  follows  the  scheme  of  instruction  used  by 
him,  and,  beginning  with  the  simplest  type  of  mold,  endeav- 
ors to  lead  the  student  and  apprentice  gradually  through  the 
more  difficult  lines  of  work  in  green  and  dry  sand  and  loam. 
From  the  many  possible  examples  which  might  have  been 
used  to  illustrate  the  different  practices,  only  those  have  been 
selected  which  are  typical  of  the  class  of  work  to  which  they 
belong.  It  is  recommended  that  the  reader,  whenever  pos- 
sible, supplement  his  study  of  this  book  by  actually  making 
molds  of  the  character  described  in  the  various  chapters.  It 
is  impossible  to  learn  the  art  of  molding  by  reading  only. 

Such  other  matters  as  the  student  of  foundry  work  should 
be  acquainted  with  are  included  in  the  book,  these  including 
the  subjects  of  cupola  practice,  mixing  and  melting,  cleaning 
and  repair  of  castings,  etc. 

The  author  has  endeavored  to  make  a  text-book  for  the 
student,  apprentice,  and  molder,  rather  than  a  reference  work 
for  the  finished  foundryman.  His  thanks  are  due  to  Mr. 
Robert  Thurston  Kent,  M.E.,  for  editing  the  manuscript  and 
reading  the  proofs. 

R.  H.  PALMER. 

BELMONT,  ALLEGANY  Co.,  N.  Y., 
October  i,   1911. 


iii 


CONTENTS 

CHAPTER  PAGE 

I.  THE  MOLD — ITS  FORM  AND  THE  METHODS  OF  MAKING  IT,    .    .  i 

Molding  a  Split  Pattern,       8 

Molding  a  Split  Pattern  with  a  Web  Center 12 

II.  IRREGULARLY  SHAPED  PATTERNS, 15 

Molding  a  Hand  Wheel 17 

Coping  Down  Irregular  Patterns,        18 

Molding  in  a  Three-Part  Flask, 20 

Molding  with  a  False  Cheek, 21 

Molding  Double  Groove  Sheave  in  a  Three-Part  Flask,     .  22 

Gear  Molding, 25 

III.  FLOOR  MOLDING,       30 

Molding  Lathe-Bed  Legs, 30 

Pouring  Floor  Molds 36 

Molding  Pulleys, 37 

Molding  Bevel  Gears 39 

IV.  LIGHT  CRANE  FLOOR  WORK,       43 

Molding  Wire-cloth  Loom  Frame, 43 

V.  BEDDING  PATTERNS  IN  THE  FOUNDRY  FLOOR 48 

Molding  a  Draw-Bench  Frame  in  the  Floor, 49 

Molding  a  Gap-Press  Frame, 58 

VI.  MOLDING  COLUMNS 65 

Ornamental  Columns, 65 

Round  Columns, 69 

VII.  MOLDING  WITH  SWEEPS, 75 

VIII.  MOLDING  CAR-WHEELS, 84 

IX.  SKIN-DRIED  MOLDS, 90 

Molding  an  Engine  Bed  in  a  Skin-Dried  Mold 91 

X.  DRY-SAND  MOLDS,         100 

Molding  a  Corliss-Engine  Cylinder  in  Dry  Sand,     .     .     .  101 

Molding  Printing-Press  Cylinders  in  Dry  Sand 108 

v 


vi  CONTENTS 

CHAPTER  PAGE 

XI.  LOAM  MOLDING, 116 

Molding  a  Cylinder  in  Loam 120 

Molding  Balance  Wheels  in  Loam, 128 

Loam  Mixtures, .     .  132 

Sweeping  Loam  Cores, 132 

XII.  MOLDS  FOR  STEEL  CASTINGS, 134 

XIII.  DRY-SAND  CORES,       138 

XIV.  SETTING  CORES  AND  USING  CHAPLETS, 156 

XV.  GATES  AND  GATING, 163 

Types  of  Gates 168 

XVI.  RISERS,  SHRINKHEADS  AND  FEEDING  HEADS, 174 

XVII.  TREATMENT  OF  CASTINGS  WHILE  COOLING, 176 

XVIII.  CLEANING  CASTINGS, 181 

XIX.  MOLDING  MACHINES, 184 

Power  Squeezers, 185 

Split-Pattern  Machines 190 

Jarring  Machines 194 

Roll-Over  Machines 197 

When  to  Use  a  Molding  Machine 202 

XX.  MENDING  BROKEN  CASTINGS 204 

Burning 204 

Thermit  Welding 207 

Oxy-Acetylene  Welding 208 

XXI.  MOLDING  TOOLS, 210 

XXII.  MOLDING  SANDS, 217 

Preparation  of  Sand  for  Molding, 226 

Facing  Materials, 228 

XXIII.  IRON  AND  ITS  COMPOSITION, 234 

Grading  of  Pig  Iron 237 

Specifications  for  Foundry  Pig  Iron 239 

Analyses  of  Castings, 241 

Shrinkage  of  Cast-Iron, 244 

XXIV.  THE  CUPOLA  AND  ITS  OPERATION, 245 

Calculation  of  Cupola  Mixtures, 265 


CONTENTS  Vll 

CHAPTER  PAGE 

XXV.  THE  AIR-FURNACE  AND  ITS  OPERATION, 271 

XXVI.  THE  BRASS  FOUNDRY, 275 

XXVII.  FOUNDRY  EQUIPMENT, 280 

GLOSSARY, 288 

APPENDIX, 298 

Circumference  and  Areas  of  Circles, 298 

Surface  and  Volume  of  Spheres, 304 

Weight  and  Specific  Gravity  of  Metals 307 

Melting  Points  of  Various  Substances, 308 

Strength  of  Rope, 309 

Strength  of  Chains, 310 

Analyses  of  Fire-Clay, 311 

Sizes  of  Fire-Brick 312 

Number  of  Fire- Brick  Required  for  Various  Circles, 313 

Weight  of  Castings  Determined  from  Weight  of  Pattern,     .      .      .314 

Dimensions  of  Foundry  Ladles, 314 

Composition  of  Brass  Foundry  Alloys 315 

Useful  Alloys  of  Copper,  Tin,  and  Zinc, 316 

Composition  of  Various  Grades  of  Rolled  Brass,  etc.,      .      .      .      .317 

Shrinkage  of  Castings 317 

Sizes  of  Pipes  for  Tumbling  Barrels, 318 

Diameter  of  Exhaust  Fan  Inlets  for  Tumbling  Barrels,  ....  318 

Steel  Pressure  Blowers  for  Cupolas,       .      .      .      ., 319 

Capacity  of  Sturtevant  High  Pressure  Blowers 321 

Speed,  Capacity,  and  Horse-Power  of  Sirocco  Fans,  .      .      .      .      .   322 

Capacity  of  Rotary  Blowers  for  Cupolas, 323 

Diameter  of  Blast  Pipes 324 


FOUNDRY    PRACTICE 


CHAPTER   I 

THE  MOLD— ITS  FORM  AND  THE  METHODS  OF 
MAKING  IT 

IN  all  foundry  practice,  the  mold  is  the  essential  feature. 
A  mold  is  the  form  or  cavity  in  a  refractory  material  such  as 
sand  or  loam,  or  in  metal,  into  which  molten  metal  is  run  or 
poured,  and  which  determines  the  final  shape  of  the  poured 
metal  after  cooling.  See  Fig.  I. 

While  molds  are  made  in  many  different  materials,  and  of 
many  different  shapes  and  by  different  methods,  yet  in  their 
essential  characteristics  they  are  all  alike.  They  are  all  made 
from  a  pattern,  which  may  be  of  wood,  metal,  or  other  material ; 
except  for  the  very  largest  molds,  which  are  bedded  in  the 
floor  of  the  foundry,  and  for  certain  other  special  kinds  of 
molds,  they  are  supported  by  and  enclosed  in  a  flask,  which 
may  be  either  of  wood  or  metal,  and  which  may  be  either 
rigid  or  hinged,  the  latter  being  known  as  a  snap  flask;  they 
are  formed  in  a  material  which  will  withstand  the  heat  of  the 
molten  metal  when  it  is  poured  into  the  mold,  the  more 
common  materials  being  sand,  either-dry  or  green,  loam,  plaster 
of  paris,  and  iron,  the  latter  being  used  for  chitted  work  such  as 
car  wheels,  etc.;  cavities  in  the  casting,  by  which  name  the 
final  product  of  the  foundry  is  known,  are  formed  by  means  of 
cores  which  may  be  either  baked  cores,  or  green-sand  cores. 

Molding  operations  are  variously  subdivided.  Thus, 
according  to  size,  there  is  what  is  known  as  bench  work,  usually 
for  the  lighter  class  of  castings,  and  floor  work,  for  the  heavier 
castings.  According  to  materials  of  which  the  mold  is  com- 


2  FOUNDRY    PRACTICE 

posed,  the  work  is  classified  as  green-sand,  dry-sand,  loam,  or 
chilled  work.  Another  subdivision  is  hand  work  and  machine 
work,  depending  on  whether  the  mold  is  made  by  hand  or  in  a 
molding  machine.  Each  of  these  classifications  may  be  still 
further  subdivided,  as  will  be  shown  in  subsequent  chapters. 
In  order  to  introduce  the  student  to  the  art  of  molding  we 
will  consider  the  simplest  class  of  mold,  and  discuss  the  various 
operations  in  its  production — a  green-sand  mold  made  at  the 
bench,  with  a  one-piece  pattern,  the  entire  pattern  being 


FIG.  i. — OPENED  SMALL  GREEN-SAND  MOLD  IN  SNAP  FLASK. 


placed  in  one  section  of  the  flask,  and  made  without  cores  or 
other  complications. 

In  order  that  the  description  of  the  actual  molding  opera- 
tions may  not  be  burdened  with  descriptions  of  tools  and 
equipment,  more  or  less  irrelevant,  and  yet  which  are  used  in 
the  work,  it  will  be  assumed  for  the  time  being  that  the  reader 
is  familiar  with  these,  and  with  their  use.  Each  piece  of  equip- 
ment and  every  tool  mentioned,  however,  is  described  in 
detail  in  Chapter  XXI  devoted  to  tools  and  equipment,  and 


THE    MOLD 


the  reader  is  referred  to  that  chapter  or  to  the  glossary,  page 
288,  for  such  information  as  may  be  necessary  as  to  render 
the  description  more  explicit. 

Referring  now  to  Fig.  I  ,  the  pattern  to  be  molded  is  shown 
at  A.  This  is  a  rectangular  block  eight  by  five  inches  and 
five-eighths  of  an  inch  thick.  It  is  to  be  molded  in  green  sand 
in  a  snap  flask,  the  two  parts  of  which  are  shown  at  C  and  D. 
As  the  pattern  is  quite  shallow  the  short  sides  are  parallel.  A 
deeper  pattern  will  have  a  slight  taper,  to  enable  it  to  be  with- 
drawn from  the  sand  more  readily.  This  taper  is  known  as 
the  draft.  The  lower  portion  of  the  mold,  that  contained  in 
flask  C,  is  known  as  the  nowel  or  drag.  The  upper  portion  is 
called  the  cope.  Fig.  I  also 
shows  the  usual  arrangement 
of  the  molder's  bench,  com- 
prising the  grating  on  which 
the  actual  work  is  done,  the 
sand  bin  below  it,  and  the 
tool  rack  above,  on  which  is 
shown  the  usual  equipment 
of  molder's  tools,  consisting 
of  rammers,  brush,  riddle,  bel- 
lows, and  a  tool  box  contain- 
ing his  small  tools. 


BOARD  PATTERN  ON  BOARD 

FIG.  2. — ARRANGEMENT  OF  PATTERN  AND  FLASK  ON  MOLD-BOARD. 

In  making  the  mold,  the  molder  first  places  his  mold-board 
on  the  bench,  with  the  cleats  on  the  board  extending  away 
from  him,  this  being  the  most  convenient  position  for  rolling 
over  the  drag.  The  pattern  A  is  placed  on  the  mold-board  as 
shown  in  Fig.  2,  and  the  drag  of  the  flask  placed  over  it  with 
the  pins  projecting  downward  on  either  side  of  the  board.  An 


4  FOUNDRY    PRACTICE 

iron  band  H  is  slipped  inside  the  flask  and  rests  on  lugs  or 
ears  F,  having  slots  cut  in  it  to  permit  it  to  slip  over  these  lugs. 
It  is  important  that  there  be  plenty  of  sand  over  the  pattern 
when  the  mold  is  complete,  not  only  to  prevent  the  bottom 
board  from  burning  but  to  hold  the  metal  in  the  mold.  In  the 
present  case,  the  pattern  being  shallow,  there  is  no  doubt  on 
this  score,  but  with  a  deeper  pattern  the  molder  will  place  his 
strike  across  the  top  of  the  drag  and  thus  ascertain  the  distance 
between  the  top  of  the  pattern  and  the  edge  of  the  flask,  and 
govern  his  selection  of  the  flask  accordingly.  Being  assured 
that  there  will  be  a  sufficient  depth  of  sand  over  the  pattern, 
sand  is  sifted  on  the  pattern  as  it  lies  on  the  mold-board  by 
means  of  the  riddle  until  the  pattern  is  completely  covered. 
The  molder  then  tucks  the  sand  around  the  edges  of  the  pat- 
tern with  his  fingers,  but  does  not  press  it  down  on  top  of  the 
pattern  unless  there  is  some  special  reason  for  so  doing.  The 
drag  is  next  shoveled  full  of  sand  and  heaped  high.  The  sand 
is  then  rammed  around  the  inside  of  the  flask  with  the  peen  or 
sharp  end  of  the  rammers.  The  rammer  is  held  at  this  time 
with  the  butt  inclining  toward  the  center  of  the  flask,  so  that 
the  blow  is  somewhat  outward  in  direction,  compressing  the 
sand  at  the  edges  of  the  mold.  More  sand  is  then  shoveled 
on  to  the  flask,  the  rammers  are  reversed,  and  the  entire  sur- 
face of  the  mold  rammed.  After  ramming,  the  surplus  sand  is 
scraped  off  the  mold  by  means  of  the  strike. 

In  order  that  the  mold  will  bear  firmly  at  all  points  on  the 
bottom-board,  which  is  next  placed  on  what  is  now  the  top  of  the 
drag,  loose  sand  is  thrown  on  the  mold  and  the  bottom-board 
placed  over  it  and  rubbed  to  a  firm  bearing.  Were  this  not 
done,  and  should  there  exist  any  space  between  the  bottom- 
board  and  the  mold,  the  pressure  of  the  iron  when  poured 
might  cause  the  mold  to  break  or  cause  a  distortion  of  the 
casting.  After  placing  the  bottom-board,  the  drag  is  rolled 
over,  so  as  to  bring  the  pattern,  and  also  the  joint  or  pin  side 
of  the  flask,  to  the  top,  as  shown  in  Fig.  I .  If  the  sand  has  been 
properly  rammed,  a  perfect  joint  can  be  made  by  rubbing  the 
palm  of  the  hand  over  the  surface  of  the  nowel.  If  the  ram- 


THE    MOLD 


ming  has  been  imperfectly  done,  the  sand  should  be  tucked 
around  the  pattern  with  the  fingers.  The  surface  of  the  drag, 
or  joint,  is  next  brushed  off  with  a  soft  brush  or  blown  off  with 
the  bellows,  the  former  method  being  preferred  as  it  leaves  the 
joint  in  better  condition  to  receive  the  parting  sand.  Parting 
sand  is  now  thrown  over  the  joint  to  insure  a  good  separation 
of  the  cope  and  drag,  any  excess  sand  being  blown  from  the 


FIG.  3. — PEEXIXG  THE  SAXD  AGAINST 

THE    SIDES    OF    THE    FLASK. 


FIG.  4. — BUTT-RAMMING  THE 
SURFACE  OF  THE  MOLD. 


pattern  as  it  would  cause  the  casting  to  have  a  rough  surface. 
A  small  amount,  however,  will  do  no  harm  and  will  prevent 
the  sand  in  the  cope  from  adhering  to  the  pattern. 

The  cope  D  is  next  placed  on  the  drag,  the  two  parts  of  the 
flask  being  kept  in  their  proper  relation  by  means  of  the  pins 
on  the  drag  fitting  into  the  ears  on  the  cope.  The  iron  band  H 
is  placed  in  the  cope,  although  with  this  type  of  pattern,  often 
called  a  flat-back — that  is,  a  pattern  molded  entirely  in  the 
drag,  and  with  a  flat  surface  at  the  joint — it  is  not  altogether 
necessary  as  there  is  no  side  pressure  to  be  resisted.  It  may  be 
stated  here  that  these  bands  are  necessary  only  in  snap-flask 
work.  The  gate-stick  which  forms  the  hole  through  which 


6  FOUNDRY    PRACTICE 

the  metal  is  poured  into  the  mold  is  next  placed  in  position, 
being  driven  down  a  slight  distance  in  the  sand  of  the  drag. 
In  ramming,  it  is  important  that  the  sand  should  be  firmly 
rammed  around  the  edges  of  the  flask  with  the  peen  end  of  the 
rammer  in  order  that  it  will  withstand  the  side  pressure  of  the 
molten  metal.  Care  should  also  be  used  to  keep  the  peen 
end  of  the  rammer  not  less  than  one  and  one-quarter 
inches  away  from  the  pattern  when  ramming,  as  the  sand 
must  be  porous  enough  to  allow  the  gases  to  escape  when  the 
metal  is  poured  into  the  mold.  A  mold  can  be  rammed  too 
hard  and  it  also  can  be  rammed  too  soft.  The  proper  degree 
of  firmness  can  be  learned  only  by  experience. 

The  gate-stick  is  withdrawn  from  the  sand  and  the  cope 
is  next  lifted  from  the  drag  and  placed  at  one  side  as  shown 
in  Fig.  i.  Any  imperfections  left  on  the  cope  which  are  not 
desired,  are  smoothed  off  with  the  slicker.  These  imperfections 
consist  of  excrescences  on  the  mold  due  to  holes  or  other  imper- 
fections in  the  pattern.  In  finishing  the  mold  the  cope  should 
be  perfected  before  the  pattern  is  drawn  from  the  drag,  as  in 
case  of  damage  to  the  cope  the  sand  can  be  knocked  out  and 
the  cope  rammed  up  a  second  time,  whereas  this  would  be  im- 
possible had  the  pattern  been  removed  from  the  drag. 

The  hole  left  by  the  gate-stick  is  beveled  over  at  the  joint 
so  that  the  molten  iron  entering  the  mold  will  not  wash  sand 
in  with  it.  The  hole  left  by  the  gate-stick  at  the  top  of  the 
cope  is  reamed  out  to  a  bell-shape  to  facilitate  pouring  of  the 
metal.  The  sand  around  the  pattern  is  next  dampened  by 
water  squeezed  from  the  swab,  which  is  passed  gently  around 
the  edges  of  the  pattern,  care  being  taken  to  prevent  the  water 
from  running  on  the  pattern,  which  if  constantly  repeated, 
would  cause  the  pattern  to  swell  and  become  distorted.  The 
object  of  wetting,  or  boshing,  the  sand  around  the  pattern  is 
to  cause  the  various  grains  of  sand  to  cohere  and  to  prevent 
the  sand  from  breaking  when  the  pattern  is  withdrawn.  The 
pattern  is  withdrawn  by  means  of  the  draw-nail,  which  is 
driven  into  the  pattern.  The  molder  grasps  the  draw-nail  with 
his  left  hand  and,  by  means  of  a  rapping-iron,  jars  the  pattern 


THE    MOLD  7 

loose  in  sand  by  striking  the  draw-nail  a  few  sharp  blows, 
first  on  one  side  and  then  on  the  other,  close  to  the  pattern. 
He  then  lifts  the  pattern  vertically  upward,  using  the  draw- 
nail  as  a  handle,  at  the  same  time  rapping  it  gently  with  his 
rapping-iron.  When  the  pattern  has  been  lifted  to  a  point 
where  the  molder  can  feel  that  it  is  free  from  the  sand,  he 
balances  it  and  moves  it  up  and  down  slightly  to  make  sure 
that  it  is  entirely  free  and  then  with  a  quick  motion  lifts  it 
directly  upward  entirely  out  of  the  mold.  It  is  important 
that  the  pattern  be  drawn  straight  upward,  as  the  slightest 
sidewise  motion  will  break  the  edges  of  the  mold  at  the  joint, 
making  necessary  expensive  and  more  or  less  unsatisfactory 
repairs.  The  pattern  being  drawn,  any  imperfections  in  the 
mold  or  breaks  at  the  joint  are  repaired  with  the  slicker. 

All  imperfections  having  been  repaired,  a  channel  is  cut 
in  the  sand  from  the  impression  in  the  nowel  left  by  the  gate- 
stick,  to  the  mold.  This  channel  is  known  as  the  gate  or  sprue 
and  is  made  with  the  sprue-cutter.  It  is  shown  at  B.  At  E  a 
cavity  is  hollowed  out  in  the  cope,  being  known  as  a  cleaner. 
Any  dirt  which  may  be  washed  through  the  gate  wi.th  the  iron 
will  tend  to  rise  to  the  surface  and  be  caught  in  the  cleaner 
and  thus  be  prevented  from  passing  into  the  mold. 

These  various  operations  having  been  completed,  the  mold 
is  closed,  that  is,  the  cope  is  placed  on  the  drag,  the  pins  on  the 
drag  fitting  into  the  ears  on  the  cope  bringing  the  two  halves 
of  the  mold  into  the  same  relation  they  bore  to  each  other 
when  they  were  rammed  up.  The  mold  is  then  placed  on  the 
floor  at  a  point  convenient  for  pouring  metal  into  it  and  the 
fastenings  on  the  flask  are  loosened,  the  flask  opened  up,  and 
removed  from  the  mold.  Weights  as  shown  in  Fig.  5  are 
placed  on  top  of  the  cope  to  hold  it  down  firmly  on  the  drag 
while  the  metal  is  being  poured  into  it  and  to  prevent  the 
metal  from  working  its  way  out  of  the  mold  through  the 
joint.  At  this  point,  the  importance  of  striking  the  sand 
evenly  from  the  top  of  the  cope  becomes  evident,  for,  should 
the  weight  not  bear  evenly  at  all  points  on  the  surface  of  the 
cope,  the  pressure  of  the  iron  in  the  mold  will  lift  the  cope 


8  FOUNDRY    PRACTICE 

away  from  the  drag  on  the  side  on  which  the  weight  does  not 
bear,  and  allow  the  iron  to  flow  out  at  the  joint,  this  being 
known  as  a  run-out.  Furthermore,  if  the  weight  does  not 
bear  all  over  the  cope,  a  "strained  casting"  or  one  thicker  than 
desired  will  result,  often  causing  the  rejection  of  the  casting. 
The  molds  are  placed  on  the  floor  for  pouring  as  close  together 


FIG.  5. — MOLDS  WEIGHTED  FOR  POURING. 

as  possible  as  shown  in  Fig.  5,  only  enough  room  being  left 
between  the  different  rows  of  molds  to  permit  the  molder  to 
pass  with  his  ladle.  Here  again  the  importance  of  proper 
weighting  is  evident,  since  the  molder  is  in  serious  danger  of 
being  burned  in  the  event  of  a  break-out  while  pouring. 

MOLDING  A  SPLIT  PATTERN 

Where  the  pattern  is  of  such  shape  that  it  would  be  incon- 
venient or  impossible  to  mold  it  with  the  pattern  entirely  in 
the  drag,  a  split  pattern  is  employed.  Such  a  pattern  is  shown 


THE    MOLD  9 

in  Fig.  6  and  the  mold  made  from  this  pattern  in  Fig.  7.  This 
mold  also  illustrates  the  use  of  green-sand  cores.  One  half  the 
mold  is  in  the  drag  and  the  other  half  in  the  cope.  The  line 
B,  Fig.  6,  on  which  the  pattern  is  separated  is  known  as  the 
parting.  Referring  now  to  Fig.  6,  the  method  of  molding  is 
shown.  The  mold  board  J  is  placed  as  was  the  case  for  the 
rectangular,  one-piece  pattern  described  above  and  the  drag 
half  of  the  pattern  D  is  placed  as  shown  on  the  mold  board  with 


PATTERN  ON  MOLDBOARD 


SIDE  VIEW  OF  PATTERN 


FIG.  6. — METHOD  OF  MOLDING  A  SPLIT  PATTERN*. 


the  parting  down.  The  drag  of  the  flask  with  its  iron  band  L 
is  placed  in  position  exactly  as  was  the  case  with  the  pattern 
described  above.  Sand  is  next  riddled  on  to  the  pattern  and 
tucked  down  with  the  fingers  into  the  pockets  between  the 
ribs  R  and  the  ends  5  and  laid  up  against  the  side  of  the  pat- 
tern. The  drag  is  then  rammed  up  as  in  the  first  case,  the 
bottom-board  placed,  rubbed  to  a  bearing,  and  the  drag  turned 
over. 

On  removing  the  mold-board,  the  joint  is  made  by  rubbing 
the  sand  from  around  the  pattern  with  the  palm  of  the  hand. 
If  the  sand  has  been  properly  tucked  down  in  the  pockets  and 
around  the  sides  of  the  pattern,  there  is  no  need  of  using  a 


IO  FOUNDRY    PRACTICE 

trowel.  If  this  has  not  been  done  and  the  sand  is  too  soft 
around  the  pattern,  fresh  sand  must  be  tucked  in  and  slicked 
with  the  trowel.  The  joint  being  made,  the  cope  half  of  the 
pattern  is  placed  on  the  drag  half,  as  shown  at  M,  Fig.  6,  and 
parting  sand  is  dusted  on  the  sand  joint.  In  order  that  the 
cope  and  drag  halves  of  the  pattern  will  align  properly,  dowel 
pins  are  provided  in  the  cope  portion  as  shown  at  C,  Fig.  7, 
which  fit  in  holes  in  the  drag  at  D.  The  cope  of  the  flask  is 


FIG.  7.— MOLD  MADE  FROM  FIG. 


then  set,  as  shown  at  M,  Fig.  6,  with  the  iron  band  TV  inside 
of  it.  In  order  to  strengthen  the  green-sand  cores,  E,  the 
nails  P,  Fig.  6,  are  placed  in  position.  These  are  necessary,  as 
the  sand  has  not  sufficient  strength  to  sustain  itself  in  deep 
pockets,  such  as  we  have  here,  and  would  break  of  its  own 
weight  when  the  pattern  is  withdrawn.  The  nails  are  placed 
after  about  one-half  inch  of  sand  has  been  riddled  into  these 
pockets  in  the  pattern.  The  nails  are  wet  and  are  set  heads 
down  in  the  corners  of  the  pockets. 

The  gate-stick  is  next  placed,  sand  is  riddled  into  the  cope, 
tucked  down  around  the  nails  and  pattern,  and  the  cope  is 


THE   MOLD  II 

rammed  up.  It  should  be  remembered  when  ramming,  that 
after  having  peened  between  the  sides  of  the  flask  and  the 
pattern,  and  the  mold  is  being  rammed  with  the  butt  of  the 
rammer,  that  the  same  blow  struck  over  the  top  of  the  pattern 
will  pack  the  sand  harder  there  than  it  will  the  sand  alongside 
of  the  pattern,  due  to  the  fact  that  there  is  a  smaller  body  of 
sand  to  absorb  the  shock  of  the  blow.  As  the  molten  iron  fills 
the  mold,  it  drives  ahead  of  it  to  the  highest  parts  of  the  mold, 
the  gases  and  steam  generated  in  the  mold.  If  the  sand  has 
been  rammed  too  hard  over  the  pattern,  these  gases  may  have 
difficulty  in  escaping  through  the  sand  and,  being  pocketed 
in  the  mold,  will  expand  and  force  the  iron  back  through  the 
gate,  leaving  an  imperfect  surface  in  the  casting.  It  is  essen- 
tial, therefore,  in  ramming,  that  the  blows  struck  over  the 
pattern  shall  be  somewhat  lighter  than  those  struck  on  the 
sand  alongside  the  pattern. 

The  cope  being  rammed  up  and  struck  off,  loose  sand  is 
thrown  on  top  of  the  cope,  the  gate-stick  is  removed,  and 
the  mold-board  rubbed  down  on  the  cope  in  a  similar  manner 
to  the  bottom-board  on  the  drag.  At  this  point;  vihe.mold  is 
vented  with  a  vent-wire,  provided  a  close-grained  molding  sand 
has  been  used,  which  is  not  permeable  enough  to  permit  the 
ready  escape  of  gases  through  it.  The  venting  is  done  by 
pricking  the  sand  full  of  holes  over  the  top  of  the  pattern. 
To  vent  a  mold  properly,  it  is  essential  that  the  molder  be 
able  to  carry  in  his  mind  the  shape  of  the  pattern,  and  he 
should  trace  in  the  sand  the  outline  of  the  pattern,  as  it  lies  in 
the  flask.  Care  should  be  taken  not  to  drive  the  vent-wire 
into  the  pattern,  as  this  will  damage  the  pattern  and  cause 
imperfect  castings.  After  venting,  the  mold-board  is  placed 
and  the  cope  is  lifted  from  the  drag  and  laid  on  its  back  on 
the  board. 

The  pattern  is  next  boshed  and  is  then  removed  from  the 
mold  by  means  of  a  draw-nail.  It  is  essential  that  the  mold- 
board  be  rubbed  to  a  firm  bearing  on  the  top  of  the  cope,  other- 
wise, in  driving  the  draw-nail  into  the  pattern,  the  pattern 
will  be  driven  down  into  the  back  of  the  cope,  and  in  this  case, 


12  FOUNDRY    PRACTICE 

when  the  cope  is  turned  on  its  side  after  the  pattern  is  with- 
drawn, there  would  be  danger  of  the  sand  in  the  back  of  the 
cope  sliding  out  and  ruining  the  mold. 

The  parts  of  the  pattern  in  the  cope  and  drag  being  drawn, 
the  mold  is  finished  with  the  trowel  or  slicker,  the  gate  in  the 
cope  is  reamed  out  at  the  top,  and  the  gate  is  cut  in  the  drag 
from  the  impression  of  the  gate-stick  to  the  ribs  in  the  mold, 
as  they  form  the  deepest  parts.  (See  F,  Fig.  7.)  After  cutting 
the  cleaner  G  in  the  cope,  the  mold  is  closed,  set  on  the  floor, 
and  weighted  ready  for  pouring. 

MOLDING  A  SPLIT  PATTERN  WITH  A  WEB  CENTER 

In  Fig.  8  is  shown  a  pattern  somewhat  similar  to  that  in 
Fig.  6,  with  the  exception  that  there  is  a  web  A  at  the  center. 
The  green-sand  pockets  in  the  mold  formed  by  Fig.  6,  are  in 
this  case  cut  off  by  this  web.  The  molding  of  this  pattern  is 
similar  to  the  operation  of  molding  the  pattern  shown  in  Fig.  6. 
The  portion  of  the  pattern  with  the  web  is  molded  in  the  drag, 
with  two  bands  H  inside  the  flask.  The  principal  difference 
in  the  operation  of  molding  is  in  the  placing  of  the  nails  which 
strengthen  the  green-sand  cores.  After  the  pattern  has  been 
placed  on  the  mold-board,  sand  is  riddled  over  it  until  it  has 
a  depth  of  about  three-eighths  of  an  inch  in  the  pockets  of  the 
pattern,  after  which  nails  of  the  correct  length  are  wet  or 
clay-washed  and  set  with  the  heads  down  in  corners  of  the 
pockets.  Sand  is  then  riddled  on  the  pattern,  tucked  down,  and 
the  flask  rammed  up  as  usual.  The  nails  are  set  in  the  green- 
sand  cores  of  the  drag  to  hold  the  pockets  down  and  to  support 
the  corners,  since,  when  the  drag  part  of  the  pattern  is  rapped 
and  drawn,  the  pocket  of  sand  may  be  cracked  away  from  the 
drag  and  when  the  melted  iron  is  poured  into  the  mold  it  will 
enter  the  crack  and  float  the  sand  against  the  green-sand 
cores  of  the  cope,  thus  spoiling  the  casting.  The  nails  pre- 
vent this. 

Molding  the  cope  of  the  pattern  shown  in  Fig.  8,  is  carried 
out  in  the  same  manner  as  was  the  pattern  in  Fig.  6.  In  pat- 


THE  MOLD  13 

terns  having  pockets  too  deep  to  allow  the  use  of  nails,  wooden 
rods  or  soldiers  are  used.  These  must  be  well  soaked  with 
water  before  using,  inasmuch  as  dry  soldiers  will  absorb 
moisture  from  the  sand  and  swell,  thereby  cracking  the  mold. 
After  soaking,  the  soldiers  should  be  dipped  in  clay  wash  to 
enable  them  to  hold  to  the  sand. 

Too  much  emphasis  cannot  be  laid  on  the  fact  that  it  is 
possible  to  ram  a  mold  too  firmly  over  the  pattern.  The  proper 
degree  of  firmness  can  be  learned  only  by  experience,  but  a 
test  can  be  made  by  applying  pressure  with  the  fingers  to  the 
finished  mold.  The  face  of  the  average  small  mold,  prop- 


SIDE  VIEW  OF  PATTERN 


PATTERN  ON  MOLDBOARO 


FIG.  8. — MOLDING  A  SPLIT  PATTERN  WITH  A  WEB  IN  THE  CENTER. 


erly  rammed,  will  yield  slightly  to  pressure.  If  it  is  ram- 
med so  hard  that  it  is  unyielding  to  finger  pressure,  it  is 
certain  that  the  gases  will  be  unable  to  escape  and  a  casting 
full  of  blow-holes  will  result. 

We  have  described  above  three  simple  molding  operations 
in  green  sand.  They  are  typical  of  all  green-sand  work,  ex- 
cept that  when  large  castings  are  made,  modifications  in  the 
practice  are  necessary.  Special  arrangements  must  be  made 
for  strengthening  certain  parts  of  the  molds,  and  also  for 
venting,  as  will  be  described  in  later  chapters.  The  bulk  of 
foundry  molding  is  done  in  green  sand,  and  therefore  many  of 


14  FOUNDRY    PRACTICE 

the  later  chapters  will  take  up  in  detail  che  making  of  molds 
in  this  material,  describing  the  methods  to  be  employed  and 
the  precautions  to  be  taken. 

While  green-sand  molding  is  the  most  common,  there  are 
other  varieties  of  molds  employed  for  special  purposes,  which 
are  also  described  in  detail  later  in  the  book.  Thus  there  is  a 
skin-dried  mold  which  is  a  green-sand  mold  with  the  surface 
baked  by  means  of  an  oil  or  gas  torch  or  a  fire  basket;  the  dry- 
sand  mold  which  is  a  green-sand  mold  baked  in  an  oven,  and 
which  is  employed  for  making  steel  castings  and  in  other  situ- 
ations where  a  particularly  accurate  casting  is  desired;  the 
loam  mold  built  up  from  a  mixture  of  sand  and  clay,  backed 
with  brick  work,  employed  for  large  castings  where  the  expense 
of  pattern  work  is  to  be  avoided;  the  chill  mold  made  of  iron, 
used  for  car  wheels  and  other  castings  in  which  a  particularly 
hard,  close-grained  surface  is  desired.  These  various  molds 
all  have  their  uses  which  will  be  enumerated  together  with 
the  method  of  making  them  at  the  proper  point  in  this  book. 
For  the  present,  however,  we  will  confine  ourselves  to  the 
further  consideration  of  green-sand  molds. 


CHAPTER   II 

MOLDING  IRREGULARLY  SHAPED  PATTERNS— COPING  DOWN 

—MOLDING  IN   A    THREE-PART   FLASK— THE   USE    OF 

A    FALSE    CHEEK— MOLDING    GEARS 

THE  patterns  described  in  the  previous  chapter  have  been 
molded  on  a  plain  mold-board,  cope  side  down,  and  have  been 
rammed  up  in  the  drag.  The  joint  has  been  made  by  simply 
brushing  off  the  sand  or  slicking  it  with  the  trowel,  which  is 
all  that  is  required  with  a  pattern  having  a  plain  cope  side, 
which  allows  it  to  lie  on  the  mold-board  while  being  molded. 
In  Fig.  9,  at  C,  D,  E,  and  F,  are  shown  patterns  which  it  would 
be  impossible  to  place  on  a  plain  mold-board  and  ram  up  in 
the  drag,  since  they  would  not  remain  in  position  on  the  mold- 
board  to  cause  the  desired  portion  to  come  in  the  cope.  To 
mold  a  pattern  of  this  character,  it  is  necessary  to  cope  down, 
in  order  to  bring  the  proper  portions  of  the  pattern  in  the  cope 
and  drag  respectively,  and  also  to  permit  the  pattern  to  be 
drawn  from  the  mold. 

Referring  to  Fig.  9,  the  method  of  molding  these  four 
patterns  is  shown.  None  of  these  patterns  will  lie  in  the  cor- 
rect position  on  the  mold-board  and,  therefore,  a  rough 
bottom-board  is  placed  on  the  bench  and  on  that  an  upset,  a 
wooden  frame  of  the  required  size  and  depth,  is  placed.  The 
opening  in  the  lower  side,  adjoining  the  bottom-board,  is  a 
trifle  larger  than  that  in  the  top  side.  The  upset  is  usually 
attached  to  the  bottom-board  with  screws.  Sand  is  riddled 
into  the  upset  and  is  rammed  in  the  same  manner  as  a  flask, 
and  struck  off  level  with  the  top.  The  patterns  to  be  molded 
are  placed  on  the  sand  in  any  desirable  position.  The  sand  is 
then  dug  out  under  them,  so  as  to  allow  them  to  sink  in  the 
sand  to  the  same  depth  that  it  is  desired  they  shall  project 
into  the  cope  when  this  is  rammed  later.  The  sand  is  then 

15 


1 6  FOUNDRY    PRACTICE 

roughly  formed  around  them  and  a  little  parting  sand  dusted 
on.  In  Fig.  9,  at  A,  is  shown  the  bottom-board  with  the 
upset  B  attached  to  it,  and  the  sand  formed  in  place  as  de- 
scribed. The  drag  of  the  flask  is  next  placed  over  the  upset 
and  is  rammed  up  in  the  same  manner  as  would  be  patterns 
laid  on  a  plain  mold-board  as  described  in  Chapter  I.  After 
rolling  the  drag  over,  this  frame  of  wood  with  the  sand  in  it, 
is  lifted  off  and  the  parting  is  made  to  follow  the  shape  of  the 


FIG.  9. — MOLDING  IRREGULARLY  SHAPED  PATTERNS  WITH  A  GREEN-SAND 
MATCH. 

pattern  in  the  drag,  thus  causing  the  sand  in  the  cope  to  ex- 
tend down  on  each  side,  so  that  the  lower  side  of  the  pattern 
will  be  formed  in  the  drag  and  the  upper  side  in  the  cope. 

The  line  of  parting  having  been  determined  in  this  manner, 
the  sand  is  shaken  out  of  the  upset  and  the  frame  removed 
from  the  board.  The  frame  is  then  placed  on  the  drag  in  the 
same  manner  as  would  be  the  cope,  the  side  with  the  small 
opening  being  down.  The  frame  is  rammed  up  in  a  similar  man- 
ner to  a  cope  and  the  sand  struck  off  level  with  the  top.  The 
bottom-board  is  then  rubbed  to  a  bearing  and  screwed  to  the 


MOLDING    IRREGULARLY    SHAPED    PATTERNS  1 7 

frame.  The  upset  is  then  lifted  off,  being  now  what  is  termed 
a  green-sand  match,  as  shown  at  A ,  B.  It  is  evident  that  the 
patterns  C,  D,  E,  and  Fcan  easily  be  replaced  in  their  respec- 
tive positions  in  the  match. 

The  joint  of  the  drag  is  then  blown  off  with  the  bellows, 
fresh  parting  sand  is  dusted  on,  and  the  cope  is  rammed  up  and 
lifted  off  in  the  ordinary  manner.  The  cope  is  shown  at  G. 
The  joint  is  now  blown  off  to  free  it  of  loose  sand,  the  patterns 
are  boshed  and  drawn  from  the  drag,  after  which  the  mold  is 
finished  and  the  gate  J  cut  to  carry  the  iron  to  each  one  of  the 
impressions  left  by  the  four  patterns. 

The  casting  made  from  pattern  F  is  to  have  a  hole  in  it  at 
L.  This  hole  will  be  formed  in  the  casting  by  means  of  a  core 
which  is  shown  set  in  position  in  the  drag  at  K.  The  position 
of  the  core  is  determined  by  means  of  the  core-print  L  on  the 
pattern.  This  core-print  will  form  holes  in  the  cope  and  drag 
as  shown  at  M.  A  vent-wire  is  run  up  through  the  cope  from 
this  core-print  to  permit  the  escape  of  gas  from  the  core.  The 
venting  of  the  core  itself  is  fully  described  in  Chapter  XIII, 
devoted  to  cores.  The  mold  is  now  ready  for  closure,  weighting, 
and  pouring. 

The  green-sand  match  may  be  used  many  times  for  ram- 
ming up  the  drag  if  care  is  exercised  in  handling  it  and  in 
placing  the  patterns.  In  many  cases,  where  but  one  casting 
is  wanted  from  a  pattern,  the  cope  is  rammed  up  in  the  same 
manner  as  an  upset,  and  the  pattern  is  bedded  down  in  it  and 
the  drag  then  rammed  up.  After  the  joint  has  been  made,  the 
cope  is  knocked  out  and  is  again  rammed  up  to  form  the  cope 
of  the  mold. 

MOLDING  A  HAND  WHEEL 

Let  us  consider  the  operation  of  molding  a  hand  wheel, 
the  rim  of  which  is  set  some  distance  forward  of  the  hub. 
The  wheel  is  laid  on  a  level  mold-board  and  strips  of  wood, 
one-half  the  thickness  of  the  rim,  are  placed  under  the  drag  of 
the  flask,  in  order  to  raise  it  so  that  one-half  of  the  rim  will 
come  in  the  cope.  Sand  is  rammed  around  the  pattern,  and 
2 


1 8  FOUNDRY    PRACTICE 

when  the  drag  is  rolled  over  and  the  mold-board  removed,  the 
rim  of  the  wheel  is  found  to  be  above  the  joint  of  the  drag,  by 
just  the  thickness  of  the  wooden  strips,  this  operation  being 
termed  upsetting  the  drag.  The  joint  is  then  made  and,  as 
the  hub  of  the  pattern  is  lower  than  the  rim,  there  will  be 
quite  a  body  of  sand  to  lift  out.  The  arms  of  the  wheel  being 
rounded  on  the  edges,  will  add  more.  The  parting  is  made  by 
removing  sand  until  the  point  is  visible  where  the  pattern 
begins  to  round  under.  After  the  joint  has  been  made  and 
parting  sand  has  been  rubbed  on,  some  riddled  sand  is  laid  by 
hand  on  the  slanting  parting  in  order  to  make  the  parting 
sand  remain  in  place.  If  the  molding  sand  is  riddled  directly 
on  the  steep  parting,  it  will  slide  down  and  carry  the  parting 
sand  with  it  and  the  cope  will  stick  to  the  drag  and  break  the 
mold. 

There  will  be  a  considerable  body  of  sand  hanging  from 
the  face  of  the  cope  due  to  the  recession  of  the  hub  from  the 
rim  of  the  wheel,  and  it  is  necessary  to  support  this  by  means 
of  a  soldier,  a  piece  of  wood  in  this  case,  about  eight  inches 
long,  one  inch  wide,  and  half  an  inch  thick.  These  soldiers 
are  placed,  after  being  first  dipped  in  the  wash  pot, 
by  scraping  the  sand  from  the  pattern  adjoining  the  core- 
print  in  the  hub,  so  that  there  is  about  five-sixteenths  inch 
thickness  of  sand  outside  the  core-print.  One  soldier  is  placed 
between  the  core-print  and  the  slanting  parting  and  another 
soldier  is  placed  on  the  opposite  side  of  the  print  with  a  nail 
quartering  from  the  soldier  each  way.  This  gives  four  supports 
for  the  sand  which  is  firmly  tucked  around  them  and  rammed 
in  the  center,  using  a  gate-stick  for  a  rammer.  The  cope  is 
then  rammed  up  as  usual,  the  gate-stick  being  set  to  gate  into 
the  rim. 

COPING  DOWN  IRREGULAR  PATTERNS 

Referring  to  the  patterns  in  Fig.  10,  P  is  a  pattern  which 
can  be  molded  in  the  same  flask  with  Q.  Both  these  patterns 
require  coping  down  in  order  to  permit  the  pattern  being  drawn 
from  the  mold.  The  upset  is  rammed  full  of  sand  and  each 


MOLDING    IRREGULARLY    SHAPED    PATTERNS  19 

pattern  is  bedded  so  as  to  throw  it  into  the  cope.  The  pattern 
P  is  placed  in  the  upset  in  the  position  shown  in  Fig.  9,  being 
set  somewhat  deeper  than  the  thickness  of  the  plate  connecting 
the  two  lugs.  It  is  parted  as  described  above  down  to  the 
middle  of  the  bosses  on  the  lugs,  while  the  plate  part  of  Q  is 
placed  in  the  upset  to  the  depth  of  the  plate  containing  the 
two  square  holes.  The  drag  is  rammed  up,  rolled  over  with 
the  upset,  and  the  upset  removed.  The  joint  is  made  and,  when 


FIG.  10. — ODD-SHAPED  PATTERNS  WHICH  ARE  MOLDED  BY  COPING  DOWN 
IN  DRAG  OR  IN  COPE. 


ramming  the  cope,  soldiers  are  used  as  described  above,  for 
lifting  the  sand  around  the  lugs  while  the  hanging  sand  over 
Q  should  take  care  of  itself  with  a  properly  arranged  parting. 
Pattern  R  requires  a  flask  by  itself.  In  molding,  the  end 
which  is  foremost  in  the  illustration  is  thrown  into  the  cope 
above  the  joint,  the  other  end  of  the  pattern  being  kept  below 
the  joint.  This  pattern  is  upset  in  the  cope  and  coped  down 
from  the  drag,  requiring  a  very  irregular  joint.  The  two 
square  holes  in  the  end  are  formed  by  green-sand  cores.  It 
is  unnecessary  to  place  nails  in  these  cores  to  hold  them  as,  if 


20 


FOUNDRY   PRACTICE 


they  are  well  boshed  and  the  pattern  carefully  drawn,  they 
will  remain  in  better  shape  in  the  mold  than  if  nailed.  Often 
nails  in  small  green-sand  cores  do  more  harm  than  good,  as  in 
rapping  the  pattern,  when  drawing  it,  the  nails  in  the  core 
hold  while  the  sand  moves,  thus  breaking  the  core.  Patterns 
5  and  T  may  be  molded  in  the  same  flask  and  will  require 
some  coping  down.  The  remaining  patterns  can  be  molded 
together  as  they  can  be  best  arranged,  three  or  four  in  a  flask, 
according  to  the  ideas  of  the  molder. 

MOLDING  IN  A  THREE-PART  FLASK 

Fig.  1 1  shows  a  sheave  together  with  the  method  of  mold- 
ing it  in  a  three-part  flask.  When  molded  in  the  three-part 
flask,  the  pattern  is  laid  on  the  mold-board  in  the  center  of  the 


i  1G    r^ 
\  r-vii 

BT  \ML- 


FIG.  ii. — MOLDING  A  SHEAVE  IN  A  THREE-PART  FLASK. 

cheek  D,  as  shown  at  C,  the  parting  of  the  pattern  being  at  E. 
The  cheek  is  rammed  up  around  the  pattern,  which  operation 
tends  to  force  the  two  halves  of  the  pattern  apart  and  thus 
make  the  sheave  thicker  than  desired.  To  prevent  this,  the 
weight  F  is  placed  on  top  of  the  pattern,  while  the  cheek  is 


MOLDING   WITH   A   FALSE    CHEEK 


21 


being  rammed.  After  the  joint  in  the  cheek  is  made,  the  drag 
M  is  placed  and  rammed  up,  nails  being  placed  as  shown.  The 
cheek  and  drag  are  rolled  over  together  and  the  second  parting 
is  made,  after  which  the  cope  is  rammed  up,  nails  being  set 
as  shown  at  G.  The  cope  is  lifted  off  and  the  portion  H  of 
the  pattern  drawn,  after  which  the  cheek  is  lifted  off,  set 
aside,  and  the  portion  of  pattern  /  drawn.  After  the  core  is 
set,  the  gate  is  arranged  as  shown  at  /  in  the  cope. 

MOLDING  WITH  A  FALSE  CHEEK 

The  method  of  molding  with  a  false  cheek  is  shown  in  Fig. 
12.  The  pattern  is  placed  on  the  mold-board  as  is  shown  in 
Fig.  II,  an  upset  often  being  used  instead  of  a  cheek.  After 


E         "N 


FIG.  12. — MOLDING  A  SHEAVE  IN  A  TWO-PART  FLASK  WITH  A  FALSE  CHEEK. 

ramming  up  the  cheek,  removing  the  sand,  and  forming  the 
parting  on  the  line  K,  Fig.  12,  the  cope  is  placed  on  the  cheek 
or  upset,  being  raised  by  strips  one-half  the  thickness  of  the 
pattern,  so  that,  in  the  finished  mold,  half  the  pattern  will  be 
in  the  cope  and  the  other  half  in  the  drag.  The  arrangement 


22  FOUNDRY    PRACTICE 

is  the  same  at  this  point  as  shown  in  Fig.  1 1 ,  at  L.  The  board 
is  rubbed  to  a  bearing  on  top  of  the  cope  which  then  is  rolled 
over,  the  strips  removed,  and  a  parting  made  at  the  line  N, 
Fig.  12.  The  drag  is  placed  and  rammed  up,  the  bottom- 
board  is  rubbed  to  a  bearing,  and  the  drag  lifted  off.  Consider- 
ing now  the  flask  X,  Fig.  12,  as  a  whole,  the  false  cheek  is 
shown  between  the  lines  K  and  N,  the  cope  being  rammed  up 
on  one  side  of  it  and  the  drag  on  the  other.  The  drag  being 
lifted,  one-half  the  pattern  is  drawn,  the  parting  being  on  the 
line  E.  The  mold  is  finished  in  the  drag  and  the  drag  replaced, 
the  whole  flask  rolled,  and  the  cope  lifted.  Bearing  in  mind 
that  there  is  only  the  sand  forming  the  outside  of  the  sheave 
groove  to  hold  the  cope  part  of  the  pattern  up,  the  cope  portion 
of  the  pattern  is  carefully  drawn  from  the  sand.  The  core  is 
set,  the  cope  finished,  and  the  gate  is  punched  and  the  basin 
made  as  shown  at  J. 

MOLDING  A  DOUBLE  GROOVE  SHEAVE  IN  A  THREE- 
PART  FLASK 

Frequently  it  is  necessary  to  mold  a  double-groove  sheave 
when  only  a  three-part  flask  is  available.  The  method  of 
doing  this  is  shown  in  Fig.  13,  being  a  combination  of  the  two 
methods  above  described.  The  pattern  is  laid  on  the  mold- 
board  and  the  cheek  F  rammed  up,  after  which  the  cope  G  is 
made.  The  cheek  and  the  cope  are  rolled  over  and  the  false 
cheek  H  made  with  a  parting  at  X,  after  which  the  drag  is 
made.  The  drag  is  lifted,  together  with  a  portion  of  the  pat- 
tern L,  to  which  are  fastened  the  ribs  M.  This  portion  of 
the  pattern  is  drawn  from  the  drag,  which  is  finished  and  re- 
placed. The  entire  flask  is  then  rolled  over  and  the  cope  lifted 
together  with  the  cope  portion  of  the  pattern.  After  draw- 
ing the  pattern  the  solid  cheek  is  lifted  from  the  drag  and 
the  middle  part  of  the  pattern  drawn.  The  pattern  is  parted 
on  the  lines  C  and  D.  The  mold  is  now  finished  and 
closed.  It  may  be  poured  either  through  the  hub,  as  was 
the  first  sheave,  or  it  may  be  gated.  If  the  grooves  in  the 


MOLDING    IN    A    THREE-PART    FLASK  23 

sheave  are  very  deep,  they  should  be  supported  with  nails 
as  shown  in  Figs.  II  and  12. 

At  times,  the  sheaves  are  molded  by  using  a  pattern  with 
a  core-print  around  it  and  making  a  set  of  cores  in  a  core-box. 
After  the  pattern  is  drawn  from  the  mold,  the  cores  which 
form  the  grooves  in  the  edge  of  the  sheave  are  set.  Such  a  core 
would  occupy  the  position  of  the  false  cheek  KN,  Fig.  12. 

If  it  is  necessary  to  mold  a  sheave  from  a  solid  pattern, 
that  is,  one  without  a  parting,  the  false  cheek  may  be  formed  on 


FIG.  13. — MOLDING  A  DOUBLE  GROOVE  SHEAVE  IN  A  THREE-PART  FLASK, 
USING  A  FALSE  CHEEK. 


two  pieces  of  paper,  cut  to  the  shape  of  the  circumference  of 
the  sheave,  a  parting  being  made  by  each  sheet  of  paper. 
After  the  cope  is  lifted,  the  pieces  of  paper,  having  the  cheek 
built  on  them,  are  pulled  apart,  thus  drawing  the  sand  side- 
ways out  of  the  groove.  The  pattern  is  then  lifted  from  the 
mold  and  the  two  parts  of  the  cheek  are  pushed  together  in 
their  original  form. 

MOLDING  SOLID  SHOT 

Fig.  14  shows  the  arrangement  of  the  patterns  and  gates 
in  molding  solid  shot.  The  four  patterns  are  rammed  up  in 
the  drag,  with  the  bottom  of  the  patterns  flush  with  the  sur- 
face. Shrinkheads  or  risers  C  and  a  pouring  gate  D  are  formed 


24 


FOUNDRY    PRACTICE 


in  the  cope.  After  lifting  off  the  cope,  whirl-gates  F  are  cut 
from  the  pouring  gate  to  cause  the  iron  to  enter  the  mold 
tangentially.  This  imparts  to  the  iron  entering  the  mold  a 
swirling  motion,  which  drives  the  dirt  collected  in  the  mold 


Riier 
_>"o 
Shrink 


Joint  of  Shot  mold 


PATTERNS  DRAWN  AND  GATED 


•v  f 

O)     CO 


©     © 

COPE  SHOWING  RISERS 


FIG.  14. — MOLD  FOR  SOLID  SHOT. 


toward  the  center  and  enables  it,  therefore,  to  rise  in  the 
shrinkhead,  thus  leaving  a  clean  casting.  As  the  shrinkhead 
is  made  large  enough  to  supply  molten  iron  to  the  body  of  the 
casting  when  it  cools  and  shrinks,  a  clean,  sound  casting,  free 
from  blowholes  and  impurities,  is  secured. 


GEAR  MOLDING  25 

GEAR  MOLDING 

Gear  blanks,  that  is,  the  casting  in  which  gear  teeth  are  to 
be  cut,  must  be  free  from  dirt,  blow-holes,  and  other  imperfec- 
tions to  a  greater  degree  than  the  usual  run  of  castings.  In 
molding  gear  blanks,  the  mold  is  usually  arranged  so  that  the 
iron  will  enter  at  the  hub  in  order  that  the  face  in  which  the 
teeth  are  to  be  cut  shall  be  as  far  away  as  possible  from  the 
iron  which  first  enters  the  mold,  and  which  may  carry  with  it 
dust  or  dirt  which  will  render  imperfect  the  face  of  the  casting. 

In  molding  cast  gears,  that  is,  gears  with  the  teeth  cast  on 
them,  the  sand  must  be  selected  with  regard  to  the  size  of  the 
teeth;  the  finer  the  teeth,  of  course,  the  finer  the  grade  of  sand 
that  must  be  used.  The  sand  having  the  smallest  grains  will 
naturally  be  selected  for  those  gears  having  the  smallest  teeth, 
and  as  gears  with  larger  teeth  have  to  be  molded,  coarser- 
grained  sand  can  be  used. 

The  operation  of  molding  a  set  of  gears  will  now  be  de- 
scribed. The  patterns  being  in  position  on  the  mold-board, 
and  the  drag  of  the  flask  placed,  sand  is  riddled  over  the  pat- 
terns with  a  No.  12  riddle.  The  sand  is  carefully  tucked  in 
the  teeth  in  the  gear  pattern  and  the  drag  rolled  over  and  the 
joint  made,  coping  down  between  the  arms  of  the  gear  as  pre- 
viously described,  and  the  parting  sand  dusted  on.  It  will  be 
assumed  that  there  are  a  number  of  gears  to  be  made  from  the 
patterns,  so  therefore,  after  making  the  joint,  the  cope  is 
placed  with  an  iron  band  fitted  to  the  inside,  and  is  rammed 
up.  The  bottom-board  is  rubbed  down  on  top  of  the  cope, 
which  is  lifted  off,  placed  at  one  side,  and  the  snap  flask  re- 
moved. The  cope  part  of  the  flask  is  then  replaced  on  the 
drag  and  the  regular  cope  is  rammed  up,  lifted  off,  and  set 
on  its  side.  With  a  small  brass  tube,  a  hole  is  punched 
through  the  cope  from  the  joint  side,  in  the  center  of  the  mold 
of  the  hubs  of  the  gears  in  the  cope.  After  having  lifted  off  the 
cope,  the  patterns  are  boshed,  rapped,  and  drawn. 

The  process  of  rapping  and  drawing  a  gear  pattern  is  some- 
what different  from  the  process  of  rapping  and  drawing  an 


26  FOUNDRY    PRACTICE 

ordinary  pattern.  To  rap  a  gear  pattern  sideways  would 
distort  the  teeth  and  thus  cause  the  finished  gears  to  bind  on 
each  other  when  put  in  service.  Furthermore,  rapping  the 
pattern  sideways  would  tend  to  break  the  teeth  in  the  sand 
from  the  body  of  sand  back  of  them.  When  the  pattern  is 
withdrawn  from  the  mold,  these  broken  teeth  would  fall  and 
make  an  imperfect  casting.  In  rapping  gear  patterns,  a  raw- 
hide mallet  is  used  and  the  pattern  itself  is  tapped  slightly, 
just  enough  to  jar  it  free  from  the  sand  but  not  enough  to 
distort  or  crack  the  teeth. 

To  draw  the  pattern,  a  pair  of  tweezers  are  used,  being 
placed  in  the  drawhole  of  the  pattern  and  spread  apart  so  as 
to  fill  the  hole.  Lifting  on  the  tweezers  and  drawing  the  pat- 
tern with  his  left  hand,  the  molder  gently  taps  the  pattern  with 
his  mallet  and  as  soon  as  it  feels  free  of  the  sand,  lifts  it  clear 
of  the  mold  with  a  quick  vertical  motion.  Should  any  sidewise 
motion  be  given  the  pattern  while  drawing  it  and  a  tooth 
thereby  knocked  down,  it  will  be  economy  to  knock  the  mold 
out  of  the  flask  and  make  it  over  a  second  time,  rather  than 
attempt  to  patch  up  the  teeth. 

Care  must  be  taken  in  tucking  the  teeth  of  the  pattern  to 
have  the  sand  uniformly  firm.  Should  soft  spots  be  left  in  the 
sand  forming  the  teeth,  bunches  will  be  formed  between  the 
teeth  of  the  gear,  and  it  will  be  rough.  Should  the  sand  be 
rammed  too  hard,  the  teeth  will  stick  to  the  pattern  and  be 
broken.  Hot  iron  must  be  used  in  pouring  in  order  that  the 
gear  shall  come  out  of  the  mold  with  sharp,  clean  teeth.  A 
facing  comprising  one  part  of  bolted  seacoal  and  fourteen  parts 
of  fine  tempered  sand  should  be  used  between  the  teeth,  other- 
wise difficulty  will  be  experienced  in  cleaning  the  casting. 

To  return  now  to  the  cope  which  was  first  rammed  up  and 
set  aside.  This  is  known  as  the  false  cope  and  is  to  be  used  as 
a  match-plate  on  which  the  patterns  are  laid  when  the  second 
mold  is  made.  This  match  or  false  cope  is  placed  on  top  of 
the  bench  and  the  cope  part  of  the  flask  closed  around  it,  with 
the  joint  up.  The  patterns  are  placed  in  the  impressions  in  the 
cope,  the  drag  put  in  position,  and  sand  riddled  in  on  top  of 


GEAR   MOLDING  2J 

the  cope  in  the  same  manner  that  the  drag  was  made  for  the 
first  mold.  The  false  cope  and  drag  are  then  rolled  over  to- 
gether, the  cope  removed  and  set  aside  as  in  the  first  case,  and 
the  true  cope  made  and  finished  as  before.  The  use  of  the 
false  cope  in  this  case  is  to  avoid  making  the  joint  every  time 
a  mold  is  made.  Instead  of  using  a  false  cope,  an  upset  may 
be  employed,  having  guides  which  fit  the  pins  on  the  drag  of 
the  flask. 

At  E  in  Fig.  15,  is  shown  a  horn  gate.  The  use  of  this  is 
described  in  Chapter  XV.  After  the  drag  has  been  made,  the 
horn  gate  patterns  are  placed  in  position  as  shown  and  the 


Fie.  .15. — -METHOD  OF  MOLDING  GEAR  WHEELS,  ILLUSTRATING  USE 
OF  HORN  GATE. 

A,  Cope  of  mold-  B,  drag  of  mold  with  pattern  drawn;  C,  drag  of  mold  with  horn  gate 
pattern  set;  D,  opening  of  horn  gate  in  cope. 


cope  is  set  on  the  drag  and  rammed  up,  the  sand  being  tucked 
in  under  the  horn  gates.  These  gates  are  larger  at  one  end  than 
at  the  other,  and  after  being  boshed,  can  be  removed  from  the 
sand  by  letting  them  describe  a  sort  of  semicircle  as  they  are 
drawn.  A  gate  is  cut  in  the  center  of  the  cope  and  is  connected 
with  each  of  the  horn  gates  leading  to  the  various  gear  molds. 
The  horn  gates  are  placed  so  that  the  iron  will  flow  to  near 
the  center  of  the  gear.  The  green-sand  cores  in  the  molds 


28 


FOUNDRY    PRACTICE 


are  vented  by  means  of  a  fine  vent-wire  before  the  patterns 
are  drawn. 

MOLDING  GEARS  AND  SPLITTING  THEM 

Fig.  16  illustrates  the  method  of  molding  and  splitting  a 
bevel  gear.  The  pattern  is  shown  resting  on  the  cope,  and  in 
molding  is  placed  on  the  mold-board  in  the  same  position. 
The  drag  is  placed  around  it  with  the  pins  down.  Sand  is  rid- 
dled into  the  drag,  which  is  next  heaped  full  and  rammed  up. 
The  flask  used  in  this  case  is  a  tight  flask  and  remains  on  the 


FIG.  16. — MOLDING  AND  SPLITTING  A  BEVEL  GEAR. 


mold  when  the  latter  is  poured,  and  therefore  no  iron  band  is 
required  inside  of  it.  Before  heaping  the  sand  into  the  drag, 
the  riddled  sand  is  tucked  into  the  teeth  of  the  gears.  After 
the  drag  has  been  rammed,  it  is  rolled  over  and  the  sand  is 
scraped  away  from  the  pattern  down  to  the  ends  of  the  teeth. 
In  this  case  the  teeth  are  formed  on  an  angle  on  the  face  of  the 
drag,  and  we  are  obliged  to  cope  down  to  the  ends  of  the 
teeth  in  forming  the  joint. 


MOLDING    AND    SPLITTING    GEARS  29 

The  cope  is  then  made  up,  and  after  the  mold  has  been 
finished  and  parted,  splitting  plates,  shown  at  A,  are  set  in  the 
prints  B  in  the  mold  of  the  hub  in  the  drag.  Pouring  gates  D 
are  punched  through  the  cope  with  a  rod  or  tube  of  tke  proper 
diameter,  and  a  pouring  basin  formed  in  the  top  of  the  cope. 
The  following  points  may  well  be  borne  in  mind  in  molding 
gears:  In  boshing  a  gear  pattern  avoid  putting  any  excess  of 
water  on  the  mold,  else  it  will  be  necessary  to  dry  the  pattern 
before  using  it  again.  Hard  ramming  on  the  point  of  a  tooth 
makes  a  rounding  instead  of  a  sharp  edge.  A  gear  mold  must 
be  rammed  firmly  to  stand  the  strain  of  the  molten  metal  and 
to  keep  the  teeth  from  becoming  fat.  In  winter  the  patterns 
should  be  warmed.  At  all  times  iron  patterns  should  be 
smeared  with  barberry  tallow  mixed  with  naphtha.  The  tallow 
should  be  allowed  to  set  until  the  naphtha  has  evaporated, 
when  it  may  be  applied  to  the  pattern  with  a  stiff  brush. 
This  will  enable  the  pattern  to  be  drawn  from  the  sand  so  as  to 
leave  a  perfect  mold.  Mending  the  teeth  of  small  gear  molds 
seldom  pays.  It  is  usually  better  to  make  the  mold  over. 


CHAPTER    III 

FLOOR  MOLDING 

THE  term  floor  molding  is  applied  to  work  which  is  too 
large  for  the  bench  and  which  is  molded  either  on  the  side 
floor  or  on  the  main  floor  of  the  foundry.  The  term  is  usually 
applied  to  green-sand  work.  The  patterns  molded  on  the  side 
floor  are  those  which,  while  too  large  for  the  bench,  can  yet 
be  handled  by  one  or  several  men.  Patterns  molded  on  the 
main  floor  are  usually  those  which  require  the  services  of  a 
crane  for  handling  the  completed  mold.  Floor  molding  re- 
quires somewhat  different  equipment  from  bench  molding  and 
the  procedure  is  also  different.  The  castings  being  larger,  the 
question  of  pouring  so  as  to  secure  uniformity  in  the  finished 
casting,  without  setting  up  undue  strains  in  the  metal,  is  also 
important.  The  matter  of  pouring  will  be  discussed  at  the 
end  of  this  chapter. 

In  order  to  illustrate  the  practice  of  floor  molding,  we  will 
consider  the  molding  the  legs  of  a  lathe  bed,  shown  in  Fig.  17. 
In  the  first  place,  a  rigid  flask  is  used  instead  of  a  snap  flask. 
This  is  a  frame  of  wood  C  solidly  nailed  together,  with  tie- 
rods  extending  across  it  as  shown.  Furthermore,  while  the 
sand  in  a  small  flask,  say  up  to  fifteen  inches  square,  properly 
tempered,  will  support  itself  when  lifted  with  the  cope,  it  will 
break  away  from  the  flask  and  fall  when  the  flask  is  lifted  if 
the  latter  is  of  greater  area.  Therefore  some  provision  must 
be  made  to  support  the  sand  in  the  cope  in  the  larger  flasks 
which  are  used  in  floor  work.  This  provision  takes  the  form 
of  ribs,  such  as  are  shown  at  E  in  the  cope  of  the  flask  in  the 
background  of  Fig.  17.  These  ribs  or  bars  extend  from  one 
side  to  the  other  of  the  cope,  being  firmly  nailed  in  place.  At 
intervals,  to  keep  them  from  being  sprung  sidewise,  are  cross 
bars  M  known  as  chucks.  This  construction  forms,  in  effect, 
30 


FLOOR   MOLDING  3 1 

a  series  of  copes  extending  from  side  to  side  of  the  flask.  In 
order  to  tie  all  of  these  copes  together,  and  form  one  cope  as  a 
whole  over  the  casting,  the  sand  must  extend  under  the  bars 
and  chucks;  therefore,  the  bars  are  made  about  three-quarters 
of  an  inch  less  in  depth  than  the  depth  of  the  cope.  The  pat- 
tern which  is  under  consideration,  is  of  the  flat-back  type, 
that  is,  no  part  of  it  will  extend  up  into  the  cope.  The  bars 
then  extend  down  to  a  uniform  distance  from  the  joint  of  the 


TIG.  17. — PATTERN  OF  LATHE-BED  LEGS  LAID  ON  MOLD-BOARD  READY  FOR 
FLOOR  MOLDING. 

mold.  Should  the  pattern  be  of  such  shape  that  it  is  necessary 
for  it  to  extend  into  the  cope,  a  portion  of  the  bars  would  be 
cut  away  to  permit  the  pattern  to  fit  under  them,  and  to  allow 
a  thickness  of  about  three-quarters  of  an  inch  to  an  inch  of 
sand  to  come  between  the  pattern  and  the  bottom  of  the  bars. 
The  sand  is  necessary  not  only  to  protect  the  bars  from  com- 
ing in  contact  with  molten  iron  and  burning,  but  should 
the  wood  be  allowed  to  form  a  portion  of  the  side  of  the  mold, 
molten  iron  coming  in  contact  with  it  would  tend  to  boil  and 


32  FOUNDRY    PRACTICE 

thus  make  an  imperfect  casting.  The  edges  of  the  bars  are 
chamfered  to  a  narrow  edge  at  the  bottom,  so  as  to  divide  the 
sand  near  the  joint  as  little  as  possible. 

In  molding  the  pattern  shown  in  the  illustration,  the  mold- 
board  is  first  rubbed  to  a  firm  bearing  in  the  sand  of  the  floor, 
loose  sand  to  a  depth  of  about  two  inches  first  having  been 
shoveled  over  the  space  where  the  molding  is  to  be  carried  on. 
The  pattern  is  placed  on  the  board  as  shown  and  the  drag  of  the 
flask  set  around  it  with  the  pin  holes  G  down.  Sand  is  riddled 
on  the  pattern  and  around  it  to  a  depth  of  about  two  inches 
and  is  scraped  up  and  laid  against  the  deep  upright  sides  of 
the  pattern  until  its  entire  surface  is  covered  with  riddled 
sand.  Ten-penny  nails,  dipped  in  clay  wash,  are  set  point 
down,  one  in  each  corner  of  the  pattern  and  the  sand  tucked 
around  them.  It  is  often  advisable  in  a  deep  pattern  of  this 
character  to  vent  the  sand  in  the  corners  with  a  vent-wire. 
The  sand  is  next  shoveled  in  from  the  heap,  the  point  of  the 
shovel  being  placed  close  to  the  pattern,  and  the  sand  slid  off 
gently  into  the  flask,  to  avoid  knocking  the  riddled  sand  away 
from  the  pattern.  After  the  pattern  is  well  covered  in  this 
manner,  sand  is  shoveled  in  without  further  precaution  to  a 
depth  of  about  five  inches  and  rammed  around  the  pattern. 
In  ramming,  the  sand  should  be  struck  a  sharp  blow  with  the 
rammer  rather  than  merely  pushed  down.  In  floor  molding, 
the  long-handled  iron  rammer  is  used  and  in  this  first  operation 
is  held  peen  down,  the  sand  being  rammed  alongside  the  flask 
and  around  the  edges  of  the  pattern,  care  being  used  to  strike 
not  closer  to  the  pattern  than  one  inch.  Especial  care  must 
be  used  when  ramming  the  sand  in  the  pockets  not  to  strike 
the  pattern  or  to  ram  the  pockets  too  hard,  which  will  prevent 
the  easy  escape  of  gases  from  the  mold.  After  the  sand  has 
been  rammed  to  a  depth  equal  to  the  height  of  the  pattern,  it 
is  vented  with  the  vent-wire,  and  is  often  trodden  down  with 
the  feet.  A  second  lot  of  sand  is  then  shoveled  in  and  the  sand 
outside  the  pattern  is  rammed  with  the  butt  end  of  the  rammer 
and  also  rammed  over  that  portion  of  the  pattern  where  it  lies 
the  deepest.  At  this  stage,  the  molder  must  use  his  own  judg- 


FLOOR    MOLDING  33 

ment  as  to  how  firmly  the  mold  must  be  rammed  and  in  time 
will  be  able  to  judge  by  the  feeling  of  the  sand  under  his  ram- 
mer, whether  or  not  the  mold  is  rammed  sufficiently  hard. 
After  second  ramming,  the  flask  is  heaped  full,  trodden  down, 
rammed  with  the  butt  end  of  the  rammer,  and  struck  off  level 
with  the  top  of  the  flask.  Loose  sand  is  then  thrown  on  and  the 
bottom-board  rubbed  to  a  bearing  the  same  as  in  bench  mold- 
ing. The  board  is  then  raised  and  the  mold  well  vented,  after 
which  the  board  is  replaced  and  fastened  by  means  of  clamps, 
which  extend  from  under  the-mold-board  to  the  top  of  the  bot- 
tom-board, being  made  firm  by  wedges  driven  under  the  toes  of 
the  clamps.  The  mold  is  then  rolled  over  preferably  to  a  point 
back  of  where  the  molding  was  begun.  However,  should  the 
foundry  be  cramped  for  room,  the  flask  can  be  twisted  around 
and  lowered  on  its  original  bed,  and  the  drag  rubbed  to  a  firm 
bearing  on  the  floor,  sand  having  previously  been  thrown 
there  for  the  bottom-board  to  bed  in. 

The  clamps  are  now  removed,  together  with  the  mold- 
board,  and  the  molder  assures  himself  that  the  pattern  rests 
solidly  on  the  sand  in  the  flask.  Occasionally,  with  a  thin  pat- 
tern, the  pattern  itself  may  be  warped  and  on  the  removal  of 
the  mold-board,  a  portion  of  it  spring  up  from  the  sand.  In 
such  a  case,  the  spirit  level  should  be  placed  on  the  pattern  and 
weights  used  to  hold  the  pattern  level  until  the  joint  is  made. 
After  making  the  joint,  parting  sand  is  dusted  on,  the  weights 
removed,  and  one-half  inch  of  sand  riddled  over  the  joint.  To 
locate  the  position  of  the  gate  and  the  risers  which  are  set  in  the 
cope,  balls  of  molding  sand  are  placed  in  the  position  desired 
for  the  gate  and  risers  to  ascertain  whether  these  positions  will 
be  clear  of  the  bars  and  chucks  of  the  cope,  and  after  the  joint 
of  the  flask  and  the  pin  holes  have  been  cleaned,  the  cope  is  put 
in  position,  having  been  first  wet  or  clay-washed.  Some  of  the 
molding-sand  balls  will  probably  be  found  to  come  directly 
underneath  a  bar  in  the  cope  and  the  gate-stick  and  gaggers 
must  be  shifted  accordingly.  The  gate-stick  must  be  set  far 
enough  away  from  a  thin  pattern  of  this  character,  to  avoid 
danger  of  the  gate  breaking  into  the  mold  when  the  casting  is 
3 


34  FOUNDRY    PRACTICE 

poured.  Gaggers  (see  Fig.  138,  page  214)  are  next  set.  The 
gaggers  should  be  of  such  size  as  to  come  close  to  the  top 
of  the  bars,  but  they  should  not  project  above  if  it  can  be 
avoided.  Gate-sticks  and  gaggers  being  in  place,  sand  is 
riddled  through  a  coarse  riddle  to  a  sufficient  depth  in  the 
cope  to  permit  it  to  be  tucked  firmly  around  the  gaggers  and 
between  the  pattern  and  the  lower  edge  of  the  bars.  In  doing 
this,  the  molder  places  a  hand  on  either  side  of  the  bar  so 
that  his  fingers  can  push  the  sand  underneath  the  bar  from 
either  side.  The  sand  must  be  tucked  firmly,  otherwise 
soft  places  will  be  left  in  the  mold  which  will  cause  trouble 
when  it  is  poured.  Sand  is  shoveled  in  next  to  a  depth  of 
about  five  inches,  and  rammed  along  each  bar  with  the  peen 
of  the  rammer.  The  peen  is  then  held  transversely  to  the 
bar  and  the  sand  cross-rammed.  More  sand  is  shoveled  into 
the  flask  and  is  again  peened,  after  which  the  flask  is  heaped 
with  sand  which  is  rammed  between  the  bars  with  the  butt 
end  of  the  rammer.  The  loose  sand  is  now  struck  off  from  the 
top  of  the  flask  with  a  wedge,  special  attention  being  given  to 
the  detection  of  any  gaggers  which  may  project  above  the 
bars.  Should  such  a  gagger  be  struck  and  loosened,  the  sand 
is  immediately  punched  down  alongside  the  gagger  until  it 
holds  firm. 

The  cope  is  then  vented  all  over  and  the  gate-sticks  drawn, 
after  which  the  cope  is  lifted  off  and  placed  on  set-off  boxes, 
that  is,  a  box  having  ends  and  sides  but  no  bottom  or  top. 
One  edge  of  the  flask  is  lowered  on  to  these  boxes,  the  other 
being  raised  in  the  position  occupied  by  the  drag  in  Fig.  17, 
being  held  up  by  a  prop  at  the  back.  In  this  position  the 
molder  finishes  it,  by  first  feeling  it  all  over  to  see  that  no  soft 
spots  have  been  left  in  tucking  the  bars,  in  which  case  they  are 
repaired  by  first  cutting  up  the  sand  slightly  with  the  trowel 
and  then  pressing  fresh  sand  into  place  and  finishing  it  with 
the  trowel.  Should  soft  spots  not  be  repaired,  iron  will  force 
its  way  into  them  when  the  mold  is  poured  and  form  excrescen- 
ces on  the  casting.  The  cope  is  finished  in  the  usual  manner, 
breaks  in  the  sand  being  repaired,  and  shining  spots  in  the 


FLOOR  MOLDING  35 

sand  which  indicate  the  presence  of  gaggers  too  close  to  the 
face  of  the  mold  are  filled  in  with  fresh  sand.  The  joint  in  the 
drag  is  next  brushed  off  and  the  pattern  boshed  and  rapped  for 
drawing  from  the  sand. 

Instead  of  using  a  draw-nail  or  a  bar  set  in  a  hole  in  the 
pattern  for  rapping,  which  would  assuredly  damage  a  light 
pattern  such  as  is  shown,  the  joint  is  cut  down  in  a  number  of 
places  around  the  pattern  and  the  butt  end  of  a  wedge  placed  in 
these  cuts  against  the  pattern.  Light  blows  are  struck  with  a 
hammer  on  the  wedge  until  the  pattern  is  freed  from  the  sand. 
The  sand  is  then  built  up  at  the  spots  where  it  was  cut  out 
and  the  pattern  is  drawn  by  means  of  eye-bolts  screwed  into 
the  pattern.  In  drawing  a  pattern  of  the  kind  shown,  in  fact 
in  drawing  practically  all  patterns  used  in  floor  molding,  two 
men  are  required,  one  at  either  end.  These  must  lift  the  pat- 
tern at  exactly  the  same  time  and  each  must  be  prepared  to 
stop  lifting  at  a  signal  from  the  other  which  is  given  when 
either  notices  any  indication  of  the  sand  breaking  on  the  edges 
of  the  mold  as  the  pattern  is  lifted.  When  this  happens,  the 
sand  is  pressed  back  in  place  and  slicked  over  with  the  trowel 
before  the  pattern  is  drawn  any  further. 

The  pattern  being  drawn,  the  mold  is  carefully  looked 
over  for  imperfections  and  breaks  in  the  sand.  As  far  as  pos- 
sible, broken  sand  is  carefully  replaced  with-the  fingers,  pressed 
back  into  position  and  dampened  slightly.  The  face  of  the 
mold  is  then  finished  with  proper  tools  at  this  point,  and  the 
entire  mold  is  gone  over  in  a  similar  manner  until  all  broken 
parts  are  repaired.  Sprues  are  now  cut  from  the  upright  gates 
into  the  mold  and  the  mold  is  cleaned  of  all  loose  sand  by 
means  of  the  bellows  and  lifters.  As  any  sand  which  will  not 
blow  off,  will  not  wash  off  under  the  influence  of  molten  iron 
flowing  over  it,  the  bellows  afford  an  indication  as  to  whether 
there  are  any  loose  parts  of  the  mold  which  have  been  over- 
looked. 

On  a  thin  mold  of  this  character,  it  is  advisable  to  sprinkle 
a  light  coating  of  talc  over  which  the  iron  will  run  freely  and  a 
cooler  iron  can  therefore  be  used  in  pouring.  The  sprues  and 


36  FOUNDRY   PRACTICE 

gates  are  arranged  so  that  the  iron  will  enter  the  deeper  parts 
of  the  mold  and  also  at  the  feet.  In  a  mold  of  this  character, 
peg-gates  (see  Fig.  129,  page  171)  are  advisable.  Cores  are  next 
set  and  the  mold  is  closed.  Five  men  are  required  for  this 
operation  with  a  flask  of  this  size,  one  at  each  corner  of  the 
flask  while  the  fifth  looks  in  under  the  cope  as  it  is  closed  on 
the  drag  to  see  that  no  part  of  the  mold  falls  down.  It  is  es- 
sential that  all  four  men  lift  and  lower  the  flask  simultaneously, 
otherwise  they  may  warp  the  flask  and  thus  cause  a  portion 
of  the  mold  to  fall.  The  man  who  watches  to  see  that  this 
does  not  happen  is  called  the  "peeker." 

The  mold  is  now  clamped,  that  is,  the  cope  is  fastened  to 
the  drag  by  means  of  clamps  as  shown  at  K,  Fig.  17.  These 
U-shaped  pieces  of  iron  are  set  with  the  legs  of  the  U  projecting 
over  the  edges  of  the  cope  and  drag  respectively,  being  fast- 
ened firmly  in  position  by  means  of  wooden  wedges  L  driven 
under  the  toes  of  the  clamps.  The  usual  method  of  wedging 
the  clamps  is  to  pry  the  clamps  on  to  the  wedge  rather  than 
drive  the  wedge  home  with  a  hammer  which  might,  from  the 
force  of  the  blow,  jar  the  sand  down  into  the  mold. 

POURING  FLOOR  MOLDS 

In  pouring  this  mold,  two  ladles  are  used.  The  one  from 
which  the  iron  is  to  flow  to  the  deeper  part  of  the  mold  is 
poured  a  little  in  advance  of  the  other.  As  there  is  no  part 
of  the  casting  above  the  joint  of  the  flask  in  the  cope,  the  rising 
of  the  iron  in  the  gate  indicates  when  the  mold  is  filled.  In 
general,  in  pouring  side  floors,  the  same  ladles  are  used  as 
for  pouring  bench  molds.  A  sufficient  number  of  ladles,  how- 
ever, are  used  to  pour  the  entire  mold  at  one  time.  This  some- 
times requires  six  to  eight  ladles,  pouring  simultaneously  at 
different  gates  in  order  that  the  iron  may  reach  all  parts  of  the 
mold  in  a  fluid  condition.  A  large  wash  sink  is  a  typical 
casting  requiring  pouring  of  this  character.  In  pouring  from 
many  ladles,  the  men  all  start  and  stop  pouring  at  a  given  sig- 
nal, thus  avoiding  straining  the  casting  which  might  occur  were 


FLOOR   MOLDING  37 

iron  poured  in  the  gate  after  the  mold  is  filled,  thus  putting 
pressure,  due  to  head,  on  the  mold.  Other  classes  of  castings 
poured  in  this  manner,  include  castings  for  cotton,  woolen,  and 
other  light  machinery. 

In  pouring  the  light  and  heavy  molds  on  the  side  floor,  large 
ladles  are  often  used  holding  from  one  hundred  and  fifty  to 
three  hundred  pounds  of  iron,  in  which  case  several  men  are 
required  to  handle  the  ladle.  Many  castings  made  on  the 
side  floor  may  require  several  of  these  ladles.  It  is  advisable 
to  have  available,  in  pouring  a  heavy  casting,  approximately 
the  exact  amount  of  iron  required.  Therefore,  foundries  are 
usually  supplied  with  a  number  of  ladles  of  varying  sizes  so 
that  by  a  combination  of  sizes  the  required  amount  of  iron 
may  be  brought  to  the  mold.  It  often  is  necessary  to  pour 
One  portion  of  the  mold  with  very  hot  iron  and  another  portion 
With  slack  or  cooler  iron.  Different  gates  are  therefore  ar- 
ranged in  which  the  two  kinds  of  iron  are  poured  from  dif- 
ferent ladles.  Such  a  case  occurs  when  a  casting  has  both 
light  and  heavy  parts;  the  hotter  iron  is  fed  to  the  light  part. 
It  is  evident  from  the  foregoing,  that  floor  molding  requires 
that  consideration  be  given  to  other  points  than  the  actual 
making  of  the  mold.  It  is  impossible  in  a  book  of  this  charac- 
ter to  lay  stress  on  all  these  points  and  the  student  is  urged  to 
observe  the  methods  of  more  experienced  molders  when  gating 
and  pouring  the  various  kinds  of  castings. 

MOLDING  PULLEYS  AND  WHEELS  ON  THE  FLOOR 

A  common  job  of  floor  molding  with  green  sand  is  shown 
in  Fig.  1 8,  where  a  wheel  is  to  be  molded  and  poured  with  a 
cast  iron  rim  and  hub,  and  with  wrought-iron  spokes  set  in 
the  mold  around  which  the  iron  flows.  In  the  larger  sizes  of 
wheels  of  this  character,  provision  should  be  made  for  pouring 
the  rim  and  the  hub  separately.  The  mold  is  made  up  with 
the  rim  and  hub  pattern  in  the  usual  manner  and  after  the 
mold  has  been  opened  and  the  pattern  withdrawn,  the 
wrought-iron  spokes  are  set  in  place  as  shown.  The  ends  of 


38  FOUNDRY    PRACTICE 

the  spokes  which  are  to  come  in  contact  with  the  molten  iron 
are  coated  with  a  mixture  of  red  lead  and  benzine  or  naphtha. 
The  rim  is  first  poured,  and,  in  shrinking,  forces  the  spokes 
inward.  After  the  rim  has  cooled  the  hub  is  poured.  Wheels 
of  this  character  are  made  weighing  up  to  six  tons  and  up  to 
ten  feet  diameter.  It  is  a  quite  common  practice  to  cast  iron 
around  iron  or  steel  shafts.  If  the  shaft  should  be  given  a 
coating  of  liquid  glass  (silicate  of  soda)  prior  to  being  placed 
in  the  mold,  the  iron  will  lie  quietly  against  this  and  when  cold, 


FIG.  1 8. — MOLDING  A  WHEEL  IN  WHICH  WROUGHT-IRON  SPOKES  ARE  TO 
BE  SET. 


a  pressure  of  many  tons  will  be  necessary  to  separate  the  two. 
Aluminum  paint  often  serves  the  same  purpose  well. 

In  molding  pulleys,  the  work  is  now  ordinarily  done  on 
machines,  which  will  take  patterns  up  to,  say,  six  feet  diame- 
ter. Many  pulleys,  however,  are  still  molded  by  hand.  In 
some  foundries  it  is  customary  to  have  as  a  pulley  pattern, 
a  rim,  arms  loose  in  the  rim,  and  a  loose  hub.  In  molding, 
the  rim  is  rammed  up  in  a  cheek,  which  may  be  part  of  a 
flask  or  a  drag  staked  on  the  floor,  having  enough  chucks 
around  it  to  hold  the  sand,  if  the  mold  is  of  sufficient  size  to 


FLOOR   MOLDING  39 

require  it.  After  the  sand  is  rammed  around  the  outside  of 
the  rim,  it  is  rammed  inside  to  the  required  depth  and  a  hole 
dug  at  the  center  for  the  hub.  The  arms  are  placed  inside 
the  rims,  at  the  proper  distance  below  the  top,  and  sand  is 
tucked  under  them  and  around  the  hub,  and  the  joint  made. 
A  lifting  plate  having  projections  of  the  shape  of  the  spaces 
between  the  arms  on  its  surface,  is  placed  inside  the  pulley, 
the  two  projections  between  the  arms  being  fastened  together 
by  clamps  which  pass  over  the  arms  and  tie  all  the  plates  to- 
gether. A  lifting  screw  is  usually  placed  in  three  of  the  plates. 
The  inside  of  the  pulley,  over  the  arms,  is  rammed  up  with  the 
gate-stick  in  the  center  as  if  the  upper  half  were  molded  in  a 
cope.  After  ramming,  the  pattern  is  drawn  and  the  cheek 
lifted.  The  rim  is  finished  and  the  cope  and  drag  halves  of 
the  center  are  marked  so  that  they  can  be  replaced.  The 
upper  half  of  the  center  is  lifted  off,  the  hub  drawn,  and 
the  arms  drawn  from  the  drag  with  the  hub.  The  center  core 
is  set  and  the  cope  half  closed.  The  rim  is  then  blackened  and 
rings,  half  to  three-quarters  of  an  inch  in  thickness,  are  laid 
on  the  center,  the  runner  built,  and  the  center  weighted  for 
pouring. 

MOLDING  LARGE  BEVEL  GEARS  ON  THE  FLOOR 

Fig.  19  illustrates  the  making  of  a  large  bevel-gear  mold. 
The  pattern  A  is  placed  on  the  mold-board  as  shown,  with 
the  drag  hub  B  in  the  center.  The  cope  side  hub  is  loose  and 
is  shown  at  E.  The  drag  is  placed  with  the  joint  side  down  and 
No.  i  Albany  sand  mixed  with  seacoal  in  the  proportion  of 
five  parts  new  sand  to  five  parts  old  sand  to  one  of  seacoal  is 
tempered  and  riddled  over  the  pattern.  The  facing  is  tucked 
in  between  the  teeth  to  insure  that  the  sand  teeth  thus  formed 
shall  be  of  sufficient  hardness,  and  surplus  sand  is  then  scraped 
from  the  face  of  the  teeth  by  hand.  Facing  sand  is  next  riddled 
over  the  teeth  and  the  drag  rammed.  The  same  precautions 
must  be  observed  in  ramming  as  were  observed  in  the  making 
of  small  gears  at  the  bench,  as  described  in  Chapter  II.  After 


4O  FOUNDRY    PRACTICE 

rubbing  the  bottom-board  to  a  bearing,  the  drag  is  vented  over 
the  pattern,  care  being  taken  to  avoid  puncturing  the  sand 
teeth.  The  drag  being  rolled  over,  the  joint  is  made  by  coping 
down  around  the  pattern  to  the  bottom  of  the  outside  of  the 
teeth  as  shown  at  D,  the  sand  being  pressed  firmly  in  between 
the  teeth  with  the  fingers  while  making  the  parting.  Parting 
sand  is  rubbed  on  the  face  of  the  sand  teeth  and  the  cope  hub  E 
placed  on  the  center  of  the  pattern.  Facing  sand  is  laid  around 
the  tooth  part  of  the  joint  to  the  proper  thickness  for  setting 
the  gaggers,  and  the  cope  placed  on  the  drag.  Gaggers  are 
next  set  around  the  gear  to  lift  the  hanging  sand  formed  by 
the  outside  of  the  teeth  and  over  the  pattern. 

Sand  is  then  shoveled  in  from  the  heap,  the  flask  bars  are 
tucked,  the  gate-sticks  set  on  top  of  the  hub  to  form  the  pour- 
ing gate,  and  the  cope  rammed  up.  After  the  cope  is  lifted 
the  hub  E  is  drawn  and  the  teeth  around  the  pattern  are 
boshed.  The  pattern  is  rapped  very  lightly  as  described  in 
the  operation  of  molding  small  gears  in  Chapter  II,  and  drawn 
from  the  sand,  and  after  the  mold  is  finished,  a  light  coating  of 
talc  or  of  lead  mixed  with  talc,  is  dusted  over  the  face  of  the 
mold.  A  vent-wire  is  passed  through  the  core-print  in  the  drag 
and  core  G  of  the  proper  diameter  and  length,  is  set  after  the 
vent  hole  in  the  tapered  end  has  been  filled  with  sand  to  pre- 
vent iron  entering  the  vent  holes.  The  cope  is  then  closed  on 
the  drag.  The  gate-stick  should  be  placed  in  the  gate  hole 
before  closing  the  cope.  The  pouring  basin  H  is  built  on  top  of 
the  cope  in  order  that  a  shallower  cope  may  be  used  than 
would  be  necessary  were  the  pouring  basin  to  be  built  in  the 
flask.  It  is  thus  seen  that  the  molding  of  a  gear  on  the  floor 
is  the  same  operation  as  molding  a  small  gear  at  the  bench, 
with  the  exception  that,  there  being  a  larger  body  of  sand 
contained  in  a  larger  flask,  different  means  must  be  used  to 
secure  the  sand.  Furthermore,  the  flask  is  clamped  instead 
of  being  weighted. 

In  the  flask  N  is  seen  the  same  gear  with  cores  set  to  form 
a  split  gear  for  fastening  in  place  on  a  shaft  over  the  end  of 
which  the  gear  cannot  be  slipped.  In  molding  this  gear,  the 


FLOOR    MOLDING  4! 

mold  is  made  exactly  as  before,  but  is  gated  so  that  the  iron 
will  enter  on  either  side  of  the  splitting  cores  L  and  flow  up  as 
evenly  as  possible  on  either  side  of  them.  The  gates  are  shown 
at  S.  The  splitting  cores  L  are  extremely  thin  and  require 
special  rodding  to  strengthen  the  sand.  Instead  of  sand  cores, 
iron  plates,  of  the  same  shape  as  the  splitting  cores,  are  some- 
times used,  having  a  thick  coat  of  blacking  dried  on  them  in 
the  oven  to  protect  the  plate  from  the  molten  iron,  and  to 


FIG.  19. — MOLDING  BEVEL  GEARS  ON  THE  FLOOR. 

prevent  the  latter  from  burning  on  the  plate  when  the  mold 
is  formed.  It  is  evident  that  the  hubs  for  split  gears  must  be 
of  special  design  and  have  prints  on  them,  not  only  for  the 
center  core  but  for  the  splitting  core.  Such  hubs  are  shown  in 
the  flasks  at  N  and  0. 

In  molding  straight  tooth  spur  gears,  of  twenty-four  inches 
diameter  and  over,  it  is  customary  to  place  the  gear  pattern 
on  the  mold-board  and  to  throw  handfuls  of  sand,  taken 
from  a  heap  alongside  the  mold-board,  in  between  the  teeth. 


42  FOUNDRY    PRACTICE 

Sand  rammed  in  this  fashion  forms  very  firm  teeth.  After 
the  teeth  are  formed,  sand  is  scraped  away  from  the  outside 
of  the  pattern  and  fresh  sand  is  riddled  into  the  flask  and 
tucked  up  around  the  outside  of  the  teeth  after  which  the  mold 
is  rammed  up  as  any  other  mold  would  be. 

Gear  patterns  are  often  molded  by  using  the  floor  as  the 
drag  and  bedding  the  pattern  in  it.  Usually  where  the  face  of 
a  gear  is  quite  deep,  and  the  pattern  has  coarse  teeth,  nails  or 
pieces  of  rods  are  set  in  the  teeth  of  the  gear.  Suppose  the 
depth  of  the  face  to  be  fourteen  inches.  After  the  gear  is  ram- 
med up  a  distance  of  three  inches,  nails  or  spikes  are  laid 
radially  in  the  teeth  and  it  is  rammed  up  three  inches  more, 
after  which  additional  nails  are  inserted.  The  operation  is 
repeated  at  a  depth  of  nine  and  twelve  inches.  Thus  the  teeth 
formed  in  the  sand  will  be  fastened  by  the  nails  to  the  main 
body  of  sand  back  of  the  teeth.  They  are  thus  stronger  and 
resist  the  strains  of  pouring  better,  and  also  are  better  able  to 
sustain  the  weight  of  the  cope.  This  practice  is  adopted  only 
with  gears  of  rather  coarse  teeth  and  weighing  from  four 
hundred  pounds  to  several  tons. 


CHAPTER    IV 

LIGHT  CRANE  FLOOR  WORK 

MOLDS  which  are  to  be  made  under  the  crane,  require  con- 
siderable skill  on  the  part  of  the  molder  and  only  the  more 
experienced  men  should  be  entrusted  with  this  work,  inasmuch 
as  the  castings  made  are  large  and  the  spoiling  of  one,  due  to 
poor  molding,  involves  considerable  loss.  A  typical  mold  made 
on  the  floor  is  illustrated  in  Figs.  20  and  21,  being  one  side  of 
a  wire  cloth  loom  frame.  The  finished  casting  weighs  about 
four  hundred  and  fifty  pounds,  but  in  pouring  it,  two  ladles  are 
used  in  order  to  obtain  the  proper  distribution  of  the  iron  in  the 
mold. 

An  iron  pattern  B,  Fig.  20,  is  used.  This  is  placed  on  a 
mold-board  which  is  bedded  level  on  the  floor.  The  drag  of 
the  flask  is  placed  around  it,  joint  side  down.  The  pattern 
must  bear  firmly  on  the  mold-board,  or  else  wedges  must  be 
driven  between  it  and  the  board,  or  the  corners  of  the  board 
wedged  up  until  it  comes  in  contact  with  the  pattern.  The 
pattern  is  then  covered  with  a  mixture  of  seacoal  facing  in  the 
proportions  of  one  part  seacoal,  five  parts  new  No.  I  Albany 
sand  and  five  parts  heap  sand.  This  mixture  is  wet  with  water, 
shoveled  over,  tramped  down  and  riddled  through  a  No. 4  sieve, 
after  which  it  is  riddled  through  a  No.  8  sieve  on  to  the  pattern, 
being  then  carefully  laid  against  the  sides.  Sand  from  the 
heap  is  then  riddled  through  a  No.  3  sieve  over  the  facing  sand, 
after  which  sand  is  shoveled  in  over  the  entire  surface  to  a 
depth  of  five  inches.  Sand  is  now  rammed  adjoining  the  sides 
of  the  flask  and  around  the  pattern,  the  rammer  being  kept 
about  one  inch  from  the  pattern,  as  in  ramming  flasks  on  the 
side  floor.  The  sand  is  then  rammed  with  the  butt  end  of  the 
rammer  between  the  openings  in  the  pattern  and  in  the  remain- 
der of  the  flask,  excepting  immediately  over  the  pattern,  which 
43 


44  FOUNDRY    PRACTICE 

would  cause  the  sand  to  be  too  hard  at  this  point.  An  ad- 
ditional five  inches  of  sand  is  then  shoveled  in  and  peened  down 
along  the  edges  of  the  flask  and  trodden  down  all  over  the  drag 
and  afterward  butted  with  the  butt  of  the  rammer,  over  the 
pattern,  in  addition  to  the  other  portions.  This  operation  of 
adding  sand  and  ramming  it  with  the  butt  is  continued  until 
the  flask  is  completely  filled.  It  is  then  struck  off  and  leveled, 
the  bottom-board  placed  and  rubbed  to  a  bearing,  after  which 
the  drag  is  vented  over  the  pattern,  the  bottom-board  replaced 
and  clamped  to  the  mold-board  with  the  flask  between  them. 


FIG.  20. — PATTERN  OF  WIRE  CLOTH  LOOM  FRAME  ON  MOLD-BOARD  READY 
FOR  MAKING  DRAG. 

The  total  weight  of  the  flask,  pattern,  and  sand  is  about  forty- 
four  hundred  pounds  and  the  services  of  the  crane  will  be 
required  to  roll  it  over. 

A  chain  is  placed  around  the  drag  and  hooked  over  the 
crane  hook,  after  which  the  crane  raises  the  flask  clear  of  the 
floor.  While  suspended  in  the  air,  it  is  turned  over  and  lowered 
on  the  original  bed  of  molding  sand  with  the  mold  board  up. 
The  ends  of  the  mold-board  are  leveled,  a  spirit  level  being 
used  for  this  purpose,  and  sand  is  rammed  under  the  cleats  of 
the  bottom-board  to  maintain  the  level.  After  removing  the 
mold-board,  the  joint  is  made  as  in  ordinary  small  castings. 

Parting  sand  having  been  dusted  on  the  joint,  the  pattern 
is  covered  with  a  seacoal  facing  to  a  depth  of  three-eighths  of  an 


LIGHT   CRANE    FLOOR    WORK  45 

inch,  and  the  cope,  previously  wet  down,  is  placed  on  the  drag, 
after  which  gaggers  are  set.  'Gate-sticks  are  set  and  sand 
tucked  in  between  the  bars  of  the  flask  in  exactly  the  same 
manner  as  is  done  in  side  floor  molding. 

In  side  floor  work,  considerable  reliance  is  placed  on  the 
clay  washing  of  the  bars  of  the  cope  to  retain  the  sand  in  place, 
but  in  crane  floor  work,  the  flasks  being  larger,  careful  gag- 
gering  is  required,  as  the  bars  cannot  be  depended  on  to  hold 


FIG.  21. — DRAG  OF  WIRE  CLOTH  LOOM  FRAME  ON  FLOOR.     COPE  is  STAND- 
ING AGAINST  WALL. 


the  larger  body  of  sand.  When  placing  the  cope,  should  it  be 
found  that  it  does  not  bear  evenly  on  the  drag,  it  should  be 
clamped  down  to  it,  or  if  it  is  too  stiff  to  permit  of  this, 
the  cope  should  be  wedged  up  and  care  must  be  taken  to 
see  that  this  wedge  is  replaced  when  the  mold  is  closed  for 
pouring. 

Referring  now  to  Fig.  21,  it  will  be  noted  that  the  top  of 
the  pattern  is  coped  out  and  gaggers,  with  long  shanks,  are 
required  to  lift  the  hanging  belly  of  sand  in  the  cope.  In  set- 


46 


FOUNDRY    PRACTICE 


ting  these  gaggers,  they  are  placed  so  that  they  will  assist  in 
supporting  each  other,  and  in«proportion  to  the  size  of  the  flask 
a  greater  number  are  used  than  in  side  floor  work.  After  the 
sand  has  been  tucked  in  between  the  bars  and  the  pattern, 
sufficient  sand  is  shoveled  in  between  the  bars  of  the  cope  to 
form  a  ramming  and  the  cope  is  rammed  up  as  in  side  floor 
work.  After  the  top  has  been  scraped  off,  the  cope  is  well 
vented.  The  crane  is  then  brought  over  the  center  of  the 


FIG.  22.— WIRE  CLOTH  LOOM  FRAME  MOLD  CLAMPED  READY  FOR  POUR- 
ING AND  BOUND  DOWN  WITH  BINDER. 


cope  and  chains  are  hooked  into  staples  or  eyes  set  in  the  sides 
of  the  cope  flask  and  the  cope  lifted  and  set  to  one  side,  one 
edge  resting  on  set-off  boxes  as  shown  in  Fig.  21.  Care  must 
be  exercised  in  doing  this  as  any  jar  is  liable  to  shake  sand 
from  the  cope.  Therefore,  strain  should  be  brought  on  the 
chains  gradually,  and  lifting  and  lowering  commenced  slowly. 
It  is  almost  invariably  the  case,  that  when  the  cope  is  lifted, 
some  parts  will  be  broken  down.  When  these  are  repaired,  the 
sand  should  be  nailed  to  insure  its  remaining  in  place.  The 


LIGHT   CRANE    FLOOR    WORK  47 

cope  being  finished,  a  coating  of  silver  lead  is  applied,  over 
which  a  light  facing  of  talc  is  dusted. 

The  joint  being  brushed  off,  the  pattern  is  boshed  and 
rapped.  Eye-bolts  are  screwed  into  the  pattern  and  it  is 
lifted  from  the  sand  by  the  crane,  the  pattern  being  rapped  as 
the  crane  lifts  it.  The  mold  is  finished  and  the  gate  D  is  cut 
and  also  a  second  gate  at  E.  The  principal  body  of  iron  enters 
through  this  and  therefore  it  is  made  considerably  larger  than 
the  other.  Sharper  iron  is  poured  through  this  gate  than 
through  E.  At  X  a  gate  is  cut  to  the  riser. 

The  mold  being  finished,  cores  are  set  in  the  prints  formed 
by  the  core-prints  F  and  G  on  the  pattern.  Sand  is  slicked 
around  them  and  the  mold  coated  with  silver  lead  over  which 
talc  is  dusted.  The  cope  is  now  lowered  on  to  the  drag,  being 
guided  to  the  point  where  the  pins  enter  the  pin  holes  by  the 
wooden  guides  H.  Before  lowering  the  cope,  flour  is  placed 
on  all  the  small  cores  to  indicate  whether  or  not  the  cope 
bears  on  them.  When  the  cope  comes  to  a  bearing  one  clamp 
is  set  on  each  side  to  give  the  same  conditions  which  will  ensue 
when  the  mold  is  finally  closed.  The  clamps  are  then  removed, 
the  cope  lifted  and  examined  and  the  cores  resting  in  the  prints 
A  A  placed,  after  which  the  mold  is  closed  and  clamped  as 
shown  in  Fig.  22.  In  order  to  prevent  the  cope  springing  at 
the  center,  when  poured,  blocks  of  wood  are  set  at  either  end 
of  the  flask  and  a  rail  clamped  across  them  as  shown  in  Fig. 
22.  Wedges  are  driven  between  this  rail  and  the  bars  of  the 
flask.  Paper  is  laid  over  the  top  of  the  cope,  which  is  lighted 
when  the  mold  is  poured  and  gases  escape  from  the  vents. 
The  gases  escaping  from  the  vents  in  the  drag  will  be  lighted 
with  a  red-hot  skimmer. 


CHAPTER  V 

BEDDING    PATTERNS    IN    THE    FOUNDRY  FLOOR.— MOLDING 

A  DRAW-BENCH  FRAME  IN  THE  PIT.— MOLDING 

THE    FRAME  OF  A  GAP  PRESS 

OFTEN  large  patterns  are  molded  in  pits  in  the  foundry 
floor,  cope  and  cheek  plates  being  the  only  part  of  the  flask 
used.  In  this  way,  the  floor  is  used  as  a  drag  and  a  large  part 
of  the  expense  of  flask  manufacture  is  avoided.  In  case  the 
foundry  floor  is  damp,  tanks  of  large  size  are  sunk  in  the  floor 
and  molds  made  in  them.  If  this  is  not  done,  the  floor  being 
slightly  damp,  the  inside  of  the  pit  may  be  lined  with  tar  paper. 
Work  of  this  character  is  usually  known  as  pit  molding. 
Most  of  the  molds  made  in  pits  are  of  green  sand,  although 
skin-dried  molds  are  also  made. 

Instead  of  using  but  one  pattern  in  the  flask,  the  molder 
is,  in  many  cases,  given  patterns  of  various  sizes  and  shapes 
which  he  is  required  to  mold  in  a  certain  space  in  the  floor. 
For  instance,  at  the  foundry  of  R.  Hoe  &  Co.,  New  York, 
printing  press  manufacturers,  it  is  the  custom  for  two  molders 
to  work  together,  assisted  by  two  helpers  and  to  use  a  cast 
iron  cope  fourteen  feet  long  by  five  and  one-half  feet  wide, 
molding  in  the  floor  enough  patterns  to  fill  the  space  covered 
by  the  cope. 

The  space  allotted  to  a  molder,  on  work  of  this  character, 
is  termed  his  "floor."  When  the  number  of  castings  desired 
from  a  medium-sized  pattern  is  small,  they  often  are  molded 
in  a  hole  dug  in  the  floor.  Assume  that  there  are  several 
pipes  to  be  made,  each  three  feet  long  and  six  inches  diameter. 
A  hole  is  dug  in  the  floor  about  four  feet  long,  in  order  to  allow 
for  the  core-prints  in  the  pattern,  and  four  and  one-half  inches 
deep.  Where  the  flanges  come  on  the  end  of  the  pipes,  the 
hole  is  made  deep  enough  and  wide  enough  to  accommodate 
48 


BEDDING  PATTERNS   IN  THE  FOUNDRY  FLOOR  49 

them.  Molding  sand  is  riddled  in  the  hole  and  the  pattern 
placed  in  it  with  the  joint  side  up.  A  long  block  of  wood  being 
placed  on  top  of  the  pattern,  the  pattern  is  driven  down  into 
the  sand  the  proper  distance  by  pounding  on  the  block,  thus 
ramming  the  sand  underneath  the  pattern.  The  pattern  is 
now  weighted  in  position  and  riddled  molding  sand  laid  along- 
side of  it  by  hand.  Sand  is  then  shoveled  in  from  the  heap 
and  is  peened  down  around  the  pattern  with  the  rammer.  If 
necessary,  the  pattern  will  be  rapped  down  and  lifted  out  and 
the  flange  pattern  fixed  up,  after  which  the  pattern  is  replaced 
and  the  sides  rammed  up.  The  sand  being  rammed  even  with 
the  top  of  the  floor,  the  joint  of  the  pattern  is  made  and  the 
cope  part  of  the  flask  placed  over  the  pattern.  Parting  sand  is 
dusted  on  and  the  cope  made  up  in  the  ordinary  manner. 
Before  lifting  off  the  cope,  the  molder  drives  down  in  each 
corner  of  the  cope  on  the  outside,  an  iron  rod  or  a  wooden  stake 
about  twelve  inches  long  to  act  as  guide  when  lifting  and  re- 
placing the  cope.  The  cope  is  then  lifted  and  finished,  the 
pattern  is  drawn  and  the  drag  finished,  after  which  the  cope  is 
replaced  and  weighted  for  pouring  and  the  stakes  removed 
when  the  mold  is  ready  to  pour.  Instead  of  weighting  the  cope, 
it  may  be  held  down  by  bolting  it  by  means  of  binders  across 
the  cope,  which  engage  bolts  rising  from  binders  underneath 
the  mold.  This  method  will  be  described  in  detail  in  the 
description  of  the  next  mold. 

MOLDING  A  DRAW-BENCH  FRAME  IN  THE  FLOOR 

Having  described  the  construction  of  a  comparatively 
small  mold,  we  will  now  take  up  the  process  of  bedding  a 
rather  large  pattern  in  the  floor.  Assume  that  we  have  the 
pattern  shown  in  Figs.  23-27.  This  is  a  comparatively 
shallow  pattern,  long  and  narrow.  We  will  also  assume  that 
it  is  to  be  molded  in  a  pit  prepared  for  a  much  larger  pattern. 
The  pit  is  first  dug  in  the  foundry  floor,  say  sixteen  feet  long, 
nine  feet  wide,  and  six  feet  six  inches  deep.  Referring  to  Fig. 
28,  binders  of  cast  iron,  spaced  four  feet  on  centers,  are  placed 

4 


50  FOUNDRY   PRACTICE 

across  the  bottom  of  the  pit.  The  ends  of  the  binders  should 
be  in  line  and  the  tops  leveled  to  a  straight  edge,  after  which 
sand  is  firmly  rammed  between  and  around  them.  Each 
binder  has  a  vertical  slot  in  each  end  in  which  an  eye-bolt  with 
a  nut  and  washer  on  the  lower  end,  is  slipped,  as  shown  in  the 
illustration.  Sand  is  then  rammed  around  the  end  of  the 
binders  and  that  between  them  is  struck  off  level  with  the  top. 
Iron  plates,  one  inch  thick,  are  placed  on  top  of  the  binders, 
covering  them  and  extending  to  within  six  inches  of  the  eye- 
bolts.  Six-inch  square  timbers  are  stood  on  end  inside  of  each 
eye-bolt  and  on  top  of  the  binder.  These  pieces  of  timber  are 
allowed  to  extend  above  the  floor  line  about  four  inches.  Sand 
is  rammed  around  the  bottom  of  them  and  scantling  is  nailed 
from  one  to  the  other  at  the  top  as  shown.  The  end  timbers 
are  also  tied  across  the  ends  with  scantling. 

On  top  of  the  iron  plates  is  laid  about  five  inches  of  molding 
sand,  on  top  of  which  is  placed  a  cinder  bed,  both  firmly  ram- 
med. Over  the  cinder  bed,  straw  or  newspapers  are  placed, 
to  keep  the  sand,  which  is  later  rammed  on  top  of  the  cinders, 
from  working  down  among  them  and  filling  the  voids  in  the 
cinder  bed  which  are  depended  upon  to  bring  the  gas  from 
under  the  casting  to  pipes  which  extend  from  the  cinder  bed 
to  a  little  below  the  top  of  the  floor  line,  as  shown  in  Fig.  28. 
In  the  top  of  the  pipes,  a  plug  of  rolled  bagging  is  placed  to 
prevent  sand  entering  while  the  mold  is  being  rammed.  This  is 
removed  before  the  mold  is  poured. 

The  timbers  are  sawed  off  flush  with  the  floor  line,  a  cord 
being  used  to  give  the  proper  alignment.  This  will  give  more 
accurate  results  than  any  attempt  at  measuring  the  timbers 
and  sawing  them  off  before  placing.  The  pit  thus  prepared, 
is  for  a  pattern  four  feet  six  inches  deep.  It  can  be  used  for  a 
smaller  pattern  by  simply  filling  the  pit  to  a  greater  or  less 
depth  with  sand.  Referring  now  to  Figs.  23-27,  the  pattern  is 
placed  on  the  floor  in  the  position  in  which  it  is  desired  to 
pour  it  and  its  outline  traced  in  the  sand.  This  indicates  the 
amount  of  space  required  for  the  pattern,  which  is  then  re- 
moved and  the  pit  excavated  to  a  sufficient  depth  to  permit 


MOLDING  A   DRAW-BENCH    FRAME    IN    THE    PIT 


52  FOUNDRY   PRACTICE 

molding  the  pattern,  a  deeper  hole  being  dug  at  one  end  to 
accommodate  the  projection  on  the  pattern.  The  cinder  bed  is 
placed,  covered  with  newspapers,  and  the  gas  pipes  put  in 
position.  On  top  of  the  cinder  bed,  molding  sand  is  rammed 
to  conform  to  the  line  F  of  the  pattern,  Fig.  26.  The  pattern 
is  then  placed  in  the  pit  and  leveled  to  the  proper  height  with 
wedges  F,  Fig.  30. 

The  portion  of  the  pattern  DD,  Fig.  26,  is  removable. 
This  is  removed  and  the  remaining  portion  of  the  pattern  is 
weighted  at  the  ends,  and  facing  sand  tucked  under  the  edges 
of  the  pattern.  The  construction  of  the  pattern  is  such,  that 
this  work  can  be  done  both  from  the  inside  and  the  outside, 
while  the  weights  hold  the  pattern  in  place.  The  wedges  F 
are  removed  as  they  are  reached  in  this  operation.  Gate  cores 
are  placed  at  the  ends  of  the  pattern  and  also  upright  gates. 
Facing  sand  is  laid  up  against  the  side  of  the  pattern  and  black 
sand  is  shoveled  in  around  it  to  a  depth  of  about  five  inches 
and  is  then  firmly  rammed,  first  with  the  peen  and  then 
with  the  butt  of  the  rammer.  Inasmuch  as  these  first  ram- 
mings  of  sand  receive  the  greatest  side  strain  from  the  melted 
iron  when  the  mold  is  filled,  this  portion  of  the  operation  must 
be  carefully  done.  The  facing  sand,  lying  loose  at  the  top  and 
adjoining  the  pattern,  is  scratched  away  and  when  the  core- 
prints  C,  Fig.  26,  are  reached,  the  pins  which  hold  them  to  the 
side  of  the  pattern  are  removed.  These  pins  are  usually  made 
of  three-sixteenths-inch  wire,  one  end  of  which  is  turned  over 
and  extended  through  the  core-print  into  the  pattern. 

The  outside  being  rammed  up,  the  inside  of  the  pattern 
next  receives  attention.  Facing  sand  is  laid  against  the  sides 
of  the  pattern  and  bl$.ck  sand  is  rammed  inside.  When  the 
sand  has  reached  the  proper  height,  five-eighths-inch  iron 
rods  are  driven  down  in  the  green-sand  core,  formed  inside 
the  pattern,  as  shown  at  G,  Fig.  30.  The  pattern  is  faced  and 
sand  rammed  up  in  it  until  it  is  within  three-quarters  of  an 
inch  of  the  top,  when  the  sweep  D,  Fig.  27,  is  used  to  true  the 
facing  sand  in  the  last  three-quarters  of  an  inch.  The  green- 
sand  core  is  vented,  care  being  taken  that  the  vent-wire  passes 


MOLDING  A  DRAW-BENCH  FRAME   IN   THE   PIT 


53 


through  the  newspapers  or  straw  into  the  cinder 
vents  are  then  filled  with  sand  at  the  top  and  the 
top  of  the  mold  is  made  up  with  the 
fingers.  The  covering  boards  forming 
the  top  of  the  pattern  are  then  re- 
placed and  the  joint  is  made  level 
with  the  upper  surface  of  the  pattern. 
The  joint  being  made,  parting  sand 
is  dusted  on,  the  cope  is  placed, 
rapped  down,  staked,  and  then  hoisted 
off.  Attention  is  here  called  to  the 
manner  in  which  the  cope  is  barred 
through  the  center  as  shown  in 

Fig-  31. 

Facing  sand  is  next  spread  over 
the  pattern  and  the  joint,  after  which 
the  cope,  first  being  wet  down  or 
clay-washed,  is  lowered  into  place. 
Gate-sticks  and  gaggers  are  set,  black 
sand  is  riddled  into  the  cope  and 
tucked  in  between  the  bars  and  pat- 
tern. Sand  is  then  shoveled  into  the 
cope  to  a  depth  of  about  five  inches 
and  rammed  with  the  peen  of  the 
rammer.  Enough  rammings  of  sand 
are  added  to  fill  the  cope  level  full. 
The  final  ramming  of  sand  is  butted 
with  the  rammer  and  the  excess  sand 
cleaned  off.  In  ramming  up  the  cope, 
the  space  between  the  lines  of  chucks, 
CC,  Fig.  31,  is  not  rammed  up  with 
sand,  but  is  left  open  and  the  cope 
well  vented. 

The  gate-sticks  are  now  removed 
and  the  cope  hoisted  off.  The  joint  is 
brushed  off  and  the  mold  is  vented 
all  around  the  pattern  at  a  dis- 


bed 
face 


,    The 
at  the 


54  FOUNDRY    PRACTICE 

tance  of  about  one  and  one-quarter  inches  from  the  edge  of 
the  pattern  after  the  latter  has  been  boshed.  The  pattern 
is  now  rapped  and  drawn,  the  gate-sticks  removed,  and  the 
mold  finished  with  trowel,  slicker,  and  lifter,  and  wherever 
square  corners  of  sand  have  been  left  on  the  inside  of  the  mold 
by  the  pattern  they  are  rounded  off  to  form  fillets  in  the  cast- 
ing. This  is  a  point  which  should  always  be  remembered,  for 
unless  a  fillet  be  placed  in  the  corner  of  a  casting,  strains  will 
be  set  up  when  the  casting  cools  and  it  will  have  a  tendency  to 
break  through  the  corner. 

Referring  to  Fig.  27,  at  A  will  be  noted  a  partition  extend- 
ing the  length  of  the  casting  formed  by  a  corresponding  space 
in  the  mold.  As  the  green-sand  core  C  is  struck  off  level  at 
the  line  of  pattern  B,  this  core  extends  only  partially  into 
the  pattern.  The  balance  of  the  space  is  occupied  by  dry- 
sand  cores  hung  from  the  cope.  These  are  shown  at  E  and 
straddle  the  green-sand  core,  leaving  a  space  between  them 
and  the  green-sand  core  into  which  the  iron  flows  to  form  the 
partition  F. 

In  order  to  obtain  the  right  thickness  of  metal  on  the  sides 
of  the  casting,  pieces  of  board,  of  the  same  thickness  as  the 
casting  is  to  be,  are  placed  over  the  green-sand  core,  after 
which  the  cores  E  are  lowered  into  position  on  these  boards. 
After  they  are  correctly  placed,  the  cope,  Fig.  29,  is  lowered 
over  the  mold,  being  guided  to  place  by  the  stakes  B,  driven 
into  the  floor.  Hook  bolts  are  passed  through  the  openings 
A,  Fig.  31,  and  attached  to  staples  provided  for  the  purpose 
at  B  in  the  cores.  Gate-sticks  are  placed  at  O  where  the  gas 
is  to  escape  from  the  cores  and  wedges  are  driven  in  between 
the  bars  of  the  cope  and  the  top  of  the  cores  to  insure  the  cope 
bearing  solidly  on  the  cores  in  order  to  hold  them  in  position 
to  give  the  proper  thickness  of  metal  when  the  mold  is  poured. 

The  spaces  between  the  bars  XX  at  either  end  of  the  cope, 
and  between  chucks  C  C,  left  open  when  the  cope  was  ram- 
med up,  are  now  rammed  with  black  sand  and  the  gate-sticks 
forming  vents  are  drawn.  The  clamps  H,  Fig.  31,  are  now  laid 
in  position  as  shown  and  by  means  of  the  slotted  bars  D, 


MOLDING    A    DRAW-BENCH   FRAME   IN    THE    PIT 


55 


56  FOUNDRY   PRACTICE 

slipped  over  the  hook  bolts  to  the  cores,  previously  mentioned ; 
the  cores  are  firmly  held  in  position  by  screwing  the  nuts  on 
the  bolt  down  on  the  slotted  bar.  The  cope  is  next  hoisted 
as  is  shown  in  Fig.  29  with  the  cores  hanging  from  it. 

The  mold  is  examined,  the  boards  on  top  of  the  green-sand 
core  are  removed,  the  name-plate  core  is  placed,  and  the  cores 
X,  Fig.  30,  set  in  position.  Necessary  repairs  to  the  mold  are 
made  and  its  entire  surface  is  given  a  coat  of  silver  lead.  Gates 
are  cut  to  connect  the  upright  gates  in  the  cope  with  those  in 
the  floor.  The  cope  is  then  finally  lowered  and  held  down  with 
binders  which  span  the  pit.  Blocks  of  wood  are  placed  on  the 
cope  underneath  the  binders,  after  which  the  bolts  /,  Fig.  27, 
are  hooked  into  the  eye-bolts  in  the  floor,  the  tops  being  set  in 
the  slots  in  the  ends  of  the  binders,  when  by  screwing  down  the 
nuts,  the  binders  are  made  to  bear  firmly  on  the  cope.  Care 
should  be  taken  in  tightening  the  binders  as  the  nuts  at  the 
end  will  exert  considerable  leverage  and  crush  the  mold  if 
screwed  down  too  far. 

Runner  boxes,  shown  in  Fig.  27,  at  the  ends  of  the  cope,  are 
placed  and  runners  built  as  indicated  in  Fig.  31.  In  order  to 
avoid  any  great  head  on  the  casting,  due  to  excessive  height 
of  the  runner  boxes,  the  flow-off  D  is  built,  which  conveys  any 
excess  of  iron  to  a  basin  in  the  floor.  Gases  escape  from  the 
mold  through  the  pipes  Q,  Fig.  30,  and  through  the  gates  lead- 
ing from  the  cores.  These  gases  are  lighted  as  soon  as  they 
begin  to  flow. 

Eye-bolts,  timbers,  and  vent-pipes  are  all  kept  below  the 
floor  level  in  this  type  of  mold,  so  that  they  will  be  out  of  the 
way.  When  access  is  needed  to  them,  they  can  easily  be 
reached  by  a  slight  amount  of  digging. 

In  order  to  compare  the  foregoing  method  of  molding 
with  the  ordinary  way  of  molding  in  a  flask,  consider  what 
would  be  done  with  the  same  pattern  in  a  flask.  It  would  be 
placed  on  the  mold-board,  cope  side  down,  with  a  drag  around 
it  as  in  Fig.  32.  The  pattern  would  be  faced  with  facing  sand 
on  the  outside  and  the  sand  rammed  in  alongside  the  pattern 
as  in  molding  any  plain  pattern,  until  the  top  of  the  pattern 


MOLDING  A   DRAW-BENCH   FRAME   IN   THE    PIT 


57 


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FOUNDRY    PRACTICE 


is  reached.    The  upright  gates  B  and  the  inlet  gates  D  would 
then  be  placed  as  shown,  the  inside  of  the  pattern  cleaned  out, 

faced,  and  the  green-sand  core 
formed,  rods  being  placed  as 
before  and  the  core  vented. 
The  remainder  of  the  drag  then 
would  be  rammed  up,  the  sand 
struck  off,  and  the  bottom- 
board  rubbed  to  a  bearing.  The 
bottom-board  would  be  lifted 
off,  channelways  formed  in  the 
bottom  of  the  drag  by  striking 
it  with  the  strike,  edge  down, 
after  which  the  molder  would 
then  vent  the  drag  all  over. 
The  channelways  conduct  the 
gas  from  the  vents  to  the  edge 
of  the  mold.  The  bottom- 
board  would  next  be  replaced 
and  clamped  and  the  drag 
rolled  over.  After  the  joint  is 
made,  the  cope  is  made  exactly 
as  before,  the  principal  differ- 
ence being  that  the  cope  is 
guided  by  pins  on  the  flask 
instead  of  stakes  in  the  floor. 
Fig.  33  shows  the  mold  closed 
and  clamped  and  ready  for 
pouring. 

MOLDING  A  GAP-PRESS  FRAME 


In  Figs.  34-37  are  shown  the 
patterns  of  a  gap-press  frame, 
which  can  be  molded  in  the 
same  pit  used  for  the  patterns 
described  above.  A  pit  is  dug 


MOLDING    A    GAP-PRESS    FRAME  59 

between  the  upright  posts,  deeper  than  the  pattern,  and 
the  sand  and  cinders  riddled  and  separated.  When  the 
hole  has  a  depth  of  about  10  inches  greater  than  the  depth 
of  the  pattern,  a  cinder  bed  about  three  inches  thick  is  made 
and  gas  pipes  provided  for  carrying  gas  away  from  the 
bottom  of  the  mold  when  it  is  poured.  A  timber  D,  Fig.  36, 
is  placed  as  shown.  This  is  used  later  for  holding  the  chaplets 
supporting  the  core.  Molding  sand  is  then  rammed  up  over 
the  cinder  bed,  newspapers  first  having  been  placed  on  it,  and 
shaped  to  conform  to  the  under  side  of  the  pattern  as  nearly  as 
possible.  The  pattern  is  then  placed,  being  blocked  and 
wedged  to  its  proper  position  and  weighted  to  hold  it  in  place 
while  sand  is  being  rammed  under  it.  The  parting  of  the 
pattern  is  at  A,  Fig.  35,  and  that  part  of  the  pattern  below  the 
parting  is  bedded  in  the  pit  as  shown  in  Fig.  36.  The  core-print 
for  the  main  core  is  at  B,  Fig.  35,  and  a  flat  iron  plate  is  placed 
under  this  print  to  support  the  weight  of  the  heavy  main  core. 
A  slab  core  is  set  so  as  to  bear  against  the  face  of  the  feet,  as 
they  must  be  fairly  true  and  also  carry  a  heavy  strain  due  to 
the  weight  of  the  finished  casting.  Sand  is  rammed  underneath 
and  facing  is  tucked  under  the  pattern,  the  wedges  and  blocks 
being  removed  as  they  are  reached  and  replaced  with  firmly 
rammed  sand.  When  the  pattern  is  finally  resting  on  a  bed 
of  sand,  the  stakes  AA,  Fig.  37,  are  driven  and  the  pattern 
lifted  from  the  pit.  The  entire  face  of  the  mold  is  well  vented, 
the  vents  extending  down  into  the  cinder  bed.  The  face  of 
the  mold  is  then  made  up  with  the  fingers  and  finished  as  far 
as  possible,  after  which  the  pattern  is  replaced  and  rapped 
down  to  a  solid  bearing.  The  stakes  are  now  removed,  facing 
sand  laid  against  the  pattern,  and  black  sand  is  rammed  solid- 
ly around  it,  struck  off,  and  the  joint  made.  The  joint  being 
made,  parting  sand  is  dusted  on  the  joint,  and  the  cope  half  of 
the  pattern  placed  on  the  drag.  The  cope,  Fig.  38,  is  lowered 
over  the  pattern  and  staked  in  place  with  stakes  X,  after  which 
it  is  lifted  and  wet  down  or  clay-washed.  The  pattern  is  then 
coveted  with  facing  sand,  which  is  laid  up  against  any  portion 
to  which  it  does  not  adhere  readily  and  it  is  also  spread  over 


6o 


FOUNDRY  PRACTICE 


the  joint.  A  slab  core  is  placed  against  the  foot,  this  core  being 
arranged  with  a  staple  which  will  permit  it  to  be  wired  to  the 
cope.  .Gate-sticks  and  risers  are  placed  and  long-stem  gaggers 
set  in  position.  As  the  pattern  is  heavy,  it  is  necessary  to 
provide  some  means  of  supporting  it  in  the  cope,  since  it  might 


Fio-39  BjU 

THE  FINISHED  Fio.35 

CASTING         THE  PATTERN 


FiQ.34 
THE  PATTERN 


FIGS.  34-39. — MOLDING  A  GAP-PRESS  FRAME. 

fall  out  when  the  cope  is  lifted.  Accordingly,  wood  screws, 
with  eyes  in  the  end,  and  extending  through  the  cope  into 
the  pattern  are  provided.  After  the  pattern  is  covered  with 
facing  sand,  black  sand,  to  a  depth  of  about  two  inches,  is 
shoveled  in  and  rammed  with  short  iron  hand  rammers.  In 


MOLDING    A    GAP-PRESS    FRAME  6 1 

many  large  copes,  such  as  this,  the  bars  are  stopped  off  some 
distance  above  the  patterns  and  the  sand  is  shoveled  in  and 
rammed  with  these  rammers  instead  of  being  tucked  in  by 
hand  as  is  the  case  with  smaller  patterns.  The  black  sand  is 
now  filled  in,  in  several  rammings,  until  the  top  of  the  foot 
is  reached.  A  riser  for  a  flow-off  is  placed  on  top  of  the  foot 
as  it  is  the  highest  part  of  the  mold.  If  gas  pockets  in  a  mold, 
it  always  does  so  at  the  highest  point,  and  the  provision  of  a 
flow-off  to  enable  some  of  the  iron  to  run  away  from  this 
point,  will  produce  a  casting  sound  and  free  from  blow-holes. 
After  placing  the  riser,  sand  is  filled  in  the  flask  and  rammed 
until  the  cope  is  filled.  The  top  is  then  cleaned  of  loose  sand, 
well  vented,  and  the  core  at  the  foot  properly  secured.  Gate- 
sticks  and  risers  are  removed  and  the  cope  lifted  off. 

The  cope  is  set  up  on  one  side  and  the  wedges  and  rods  in 
the  eye-bolts,  holding  the  pattern  in  the  cope,  are  removed. 
The  holes  left  by  them  are  filled  up  and  the  cope  rolled  over 
on  its  back.  The  pattern  is  drawn  and  the  cope  finished  and 
given  a  coat  of  silver  lead,  which  is  rubbed  on  with  the  hand  on 
the  heavier  parts  and  brushed  on  with  a  camel's-hair  brush  on 
the  lighter.  Channelways  and  gates  are  cut  in  the  cope,  both 
to  conduct  the  iron  to  the  mold  and  to  act  as  cleaners. 

Before  the  drag  portion  of  the  pattern  is  drawn,  the  screws, 
holding  the  pattern  to  the  base,  are  removed,  freeing  the  base 
from  the  main  part  of  the  pattern.  In  the  corner  formed  by  the 
foot  of  the  bracket,  iron  rods  five-eighths  inch  diameter,  are 
driven  to  support  the  sand  when  the  iron  flows  around  this 
corner,  which  is  well  vented  down  to  the  cinder  bed.  After  this 
is  done,  the  foot  portion  of  the  pattern  is  drawn  and  the  mold 
finished.  When  finishing  the  drag  and  cope,  large-headed  nails 
are  pushed  into  the  face  of  the  mold,  around  the  jaw,  and  also 
around  the  edges  of  the  base.  This  is  to  prevent  the  heavier 
parts  of  the  casting  from  scabbing  when  the  iron  is  poured. 
When  finishing  the  cope  and  blacking  it  with  lead,  this  black- 
ing is  omitted  from  that  part  of  the  mold  forming  thin  portions 
of  the  casting,  as  there  is  a  liability  to  cold-shutting  the  iron 
with  a  heavy  facing  like  lead.  A  lighter  facing,  with  less  sea- 


62  FOUNDRY   PRACTICE 

coal,  is  used  on  these  portions.  The  mold  being  finished,  it  is 
gated  and  nails  are  pushed  down  into  the  sand  in  front  of  the 
gates,  to  keep  the  face  of  the  mold  from  being  cut  by  the  iron 
flowing  into  it.  At  one  end  of  the  mold  there  is  no  core-print 
for  the  main  core.  Consequently,  it  must  be  held  up  by  chap- 
lets.  Accordingly,  these  are  cut  to  length,  sharpened  on  one 
end,  and  driven  through  the  sand  in  the  floor,  into  the  timber 
D,  Fig.  36,  and  allowed  to  extend  above  the  face  of  the  mold 
a  distance  equal  to  the  thickness  of  the  casting,  as  shown  at 
F,  Fig.  36.  The  main  core  /  is  then  set,  one  end  resting  in  the 
core-print,  the  other  being  held  up  by  the  chaplet.  At  the  end, 
resting  in  the  core-print,  provision  is  made  for  gas  to  escape 
through  suitable  vents  in  the  mold.  Cores  K  and  L  are  next 
set  and  then  the  shaft  core,  one  end  of  which  rests  in  the  core 
K,  while  the  other  is  held  up  by  a  chaplet  G  in  the  core-print. 
The  cope  is  rolled  back  and  the  gate-stick  placed  in  the 
gate  hole.  The  runner  B,  Fig.  38,  is  built  and  an  iron  ring 
placed  around  the  riser  C.  Two  pieces  of  pig  iron  are  placed  on 
each  side  of  the  gate-stick,  forming  the  flow-off  D.  Pieces  of 
clay  one  inch  diameter,  and  a  little  higher  than  the  thickness 
of  the  casting,  are  formed  and  set  on  the  cores  at  the  points  at 
which  it  is  desired  that  the  chaplets  shall  be  placed.  The 
cope  is  closed  on  the  mold,  and  is  then  immediately  removed 
and  examined  and  repaired  if  necessary.  It  frequently  hap- 
pens in  closing  the  cope  over  the  cores  that  parts  of  the 
cope  are  broken.  In  order  to  see  that  the  cope  bears  prop- 
erly on  the  cores,  flour  or  white  sand  is  placed  on  such  parts 
as  may  be  doubtful  of  bearing  properly.  These  will  leave 
a  mark  on  the  dark  sand  of  the  mold  on  the  removal  of  the 
cope.  It  being  found  that  the  cope  bears  as  desired  on  the 
joint  and  cores,  the  vent-wire  is  run  up  through  the  cope, 
and  chaplets  are  set  at  the  points  where  the  pieces  of  clay 
have  marked  the  mold.  The  stems  of  the  chaplets  are  made 
long  enough,  so  that  when  they  are  pushed  up  through  the 
holes  in  the  cope  made  with  the  vent-wire  they  will  extend 
about  a  quarter  of  an  inch  above  the  top  of  the  cope  and 
still  leave  in  the  mold  a  length  of  chaplet  equal  to  the  thick- 


MOLDING    A    GAP-PRESS    FRAME  63 

ness  of  the  casting.  The  chaplets  are  held  from  falling  down 
by  pieces  of  soft  clay  squeezed  around  the  top  of  the  stem 
projecting  through  the  cope. 

The  vent-wire  is  also  used  to  form  outlets  through  the  cope 
for  the  gas  driven  off  from  the  cores.  Paste  is  placed  on  the 
edges  of  the  cores  so  that  the  iron  cannot  "fin"  over  them, 
and  thus  enter  the  vents  and  prevent  the  escape  of  gases  which 
would  then  back  into  the  mold  and  ruin  the  casting.  It  is 
advisable,  before  placing  the  cope  temporarily,  to  arrange 
pieces  of  thin  rope  or  belt  lacing  from  the  vent  openings  in  the 
cores  to  the  outside  of  the  mold.  These  should  be  covered  with 
sand  and  be  below  the  joints.  When  the  mold  is  finally  closed, 
and  just  before  pouring,  these  ropes  or  belt  lacings  should  be 
pulled  out,  thus  leaving  a  clear  vent  from  the  core.  If  clay 
be  filled  in  around  the  rope  or  lacing  before  sand  is  filled  in 
around  them,  it  will  be  impossible  for  iron  to  enter  these  vents, 
even  should  it  overflow  the  cores.  In  places  where  the  cope 
does  not  bear  as  it  should,  the  sand  in  the  floor  is  built  up  or 
parting  sand  is  filled  in  on  the  joint.  With  very  large  castings, 
what  is  termed  a  clay  worm — a  roll  of  common  fire  clay  about 
fourteen  inches  long — is  laid  at  the  back  of  the  gate.  This 
being  soft,  it  is  easily  flattened  by  the  weight  of  the  cope  when 
it  is  finally  closed  and  prevents  the  iron  straining  out  the 
back  of  the  pouring  gate  at  the  joint. 

The  cope  is  now  finally  closed  and  the  riser  C  covered  so 
that  nothing  will  drop  into  the  mold.  Binders  A,  Fig.  38,  are 
placed  on  top  of  the  cope  as  shown,  blocks  of  hard  wood  or 
iron  being  placed  between  the  binders  and  the  edge  of  the  cope. 
The  binders  are  held  down  by  hook  bolts  engaging  with  the 
eye-bolts  in  the  floor  as  before.  In  order  to  keep  the  main 
core  from  rising  when  iron  is  poured  in  the  mold,  the  binders 
E  are  passed  underneath  the  binders  A ,  being  held  by  wedges. 
Wedges  G  are  pushed  in  between  these  binders  and  the  top 
of  the  chaplets. 

A  certain  disadvantage  in  pouring  is  encountered  in  that 
the  jaw  portion,  which  must  be  the  strongest  part  of  the  cast- 
ing, is  heavy,  while  the  lightest  part  is  the  leg.  The  iron  must 


64  FOUNDRY   PRACTICE 

be  poured  hot  enough  to  run  to  all  the  light  parts  of  the  cast- 
ing, including  the  leg,  and  this  is  too  hot  to  give  the  best 
results  with  the  heavier  portions. 

Let  us  consider  molding  the  same  pattern  in  a  flask.  The 
drag  portion  of  the  pattern  is  placed  on  the  mold-board  and 
a  slab  core  placed  against  the  foot,  while  an  iron  plate  is  laid 
on  top  of  the  core-print.  The  drag  of  the  flask  is  set  around  the 
pattern  which  is  then  covered  with  facing  sand  and  successive 
layers  of  facing  sand  around  the  pattern  of  the  leg.  The  flask 
is  filled  up  with  rammings  of  black  sand  and  struck  off. 
Bottom-boards  are  rubbed  to  a  bearing,  the  drag  vented,  and 
the  bottom-boards  replaced.  The  clamps  are  placed  in  posi- 
tion and  the  drag  rolled  over.  The  cope  is  then  finished  as 
before. 

Still  another  method  exists  of  bedding  which  must  be 
practiced  with  many  different  styles  of  patterns.  The  pattern 
is  blocked  and  wedged  to  the  proper  height  in  the  hole  and 
black  or  heap  sand  is  tucked  and  rammed  under  it,  the  block- 
ing and  wedges  being  removed  as  reached.  When  the  pattern 
has  been  rammed  completely  on  its  under  surface,  it  is  staked 
and  removed  and  the  sand  bed  below  it  well  vented  down  to  the 
cinders.  The  entire  face  of  the  mold  is  covered  with  facing 
sand  to  a  depth  of  three-quarters  inch  and  the  pattern  replaced 
and  rapped  down  to  ram  the  facing  sand  into  the  bed  of  black 
sand.  The  vents  in  the  black  sand  take  care  of  the  gas  from 
the  facing  sand  of  which  the  face  of  the  mold  is  made. 


CHAPTER  VI 

MOLDING  COLUMNS 

CAST-IRON  columns  are  still  used  to  a  certain  extent  to 
support  the  floors  of  buildings  and  also  for  ornamental  pur- 
poses on  the  fronts.  The  illustrations,  Figs.  40-42,  show  the 
pattern  and  method  of  molding  a  rectangular  ornamental  col- 
umn. The  pattern  is  made  with  separate  side  pieces  A  to 
which  are  attached  pieces  of  moulding  to  give  an  ornamental 
finish.  These  are  pinned  on  to  the  side  pieces  so  that  they  may 
be  removed  during  the  process  of  molding.  The  pattern  itself 
is  made  solid  and  is  shown  at  B.  In  molding,  the  floor  is  used 
as  a  drag,  the  pit  being  prepared  as  described  in  Chapter  V. 

The  pattern  is  placed  in  the  pit  and  leveled  and  a  facing 
sand,  comprising  one  part  seacoal  to  fourteen  parts  molding 
sand,  is  laid  up  against  the  pattern.  Black  sand  from  the 
heap  is  rammed  firmly  against  the  facing  sand.  As  each  suc- 
cessive ramming  of  sand  is  laid  in  the  mold,  the  facing  sand 
is  firmly  rammed  against  the  pattern  with  a  hand  rammer  and 
fresh  facing  placed  against  the  pattern.  As  the  sand  in  the 
mold  rises  to  the  point  at  which  the  pieces  of  moulding  a  are 
pinned  to  the  pattern,  the  pins  holding  the  moulding  are  with- 
drawn, and  it  is  supported  by  the  sand.  The  facing  of  the 
pattern  and  the  ramming  of  black  sand  is  then  continued 
until  the  floor  line  is  reached  where  the  joint  is  made.  The 
cope  is  now  placed  in  position  and  rapped  down  to  insure  its 
bearing  solidly  on  the  sand.  If  there  is  but  a  small  amount  of 
sand  around  the  pattern  and  there  is  danger  of  the  mold  being 
crushed  in  when  securing,  the  cope,  pieces  of  board  are  placed 
under  the  cope  and  on  the  sides  near  the  center.  In  this  case 
pieces  of  plank  are  nailed  to  the  sides  of  the  cope  and  stakes  are 
driven  against  them  into  the  floor  to  act  as  guides  when  the 
cope  is  lifted  on  or  off;  otherwise  stakes  C,  Fig.  42,  are  used 
5  65 


66 


FOUNDRY   PRACTICE 


for  this  purpose.  The  cope  is  then  lifted  off  and  clay  washed  or 
wet  down ;  the  pattern  is  brushed  off,  parting  sand  placed  on 
the  joint  and  facing  sand  riddled  over  the  pattern,  except  at 
its  center.  The  facing  sand  is  left  off  the  pattern  at  the  center 
as  it  has  a  cooling  effect  on  the  iron  which,  in  this  case,  will 
be  poured  from  the  ends  of  the  mold.  Were  seacoal  facing 
to  be  used  at  the  point  where  the  flow  from  opposite  directions 


COPE  CLOSED  ON  AND  SECURED 
FIG.  42 

FIGS.  40-42. — MOLDING  AN  ORNAMENTAL  BUILDING  COLUMN  IN  THE  SAND. 

meets,  there  would  be  the  liability  of  a  cold  shut  forming  and 
thus  destroying  the  casting.  In  place  of  the  seacoal  facing 
at  this  point,  a  mixture  of  old  and  new  sand  is  used. 

The  cope  is  now  replaced,  and  gate-sticks  D  and  E  set  to 
form  the  pouring  gates  and  risers.  Gaggers  are  set  and  the 
sand  shoveled  in  to  the  proper  depth  for  tucking  the  bars. 
Extreme  care  must  be  used  in  this  operation  in  castings  of  this 
character,  since  any  soft  spots  left  in  the  mold  will  form  lumps 
on  the  casting  and  destroy  their  value  for  ornamental  purposes. 
After  tucking  the  bars,  the  cope  is  rammed  up,  vented  in  the 
usual  way,  the  cope  hoisted  off,  turned  over  on  its  back  and 


MOLDING   COLUMNS  67 

finished.  The  joint  is  brushed  off  and  the  pattern  drawn. 
The  pieces  of  moulding  a  remain  in  the  sand  when  the  pattern 
is  drawn,  and  they  now  are  drawn  inward  into  the  mold  and 
lifted  out.  Should  these  pieces  be  of  any  considerable  depth, 
thus  leaving  a  considerable  body  of  sand  hanging  over  them, 
the  mold  is  nailed  on  the  upper  surface  of  the  cavity  left  by 
these  pieces. 

The  side  pieces  A  are  now  placed  in  the  mold,  one  on  either 
side,  and  the  center  or  green-sand  core  built.  These  side  pieces 
are  the  same  thickness  as  the  casting  is  required  to  be.  A 
mixture  consisting  of  one-half  old  sand  and  one-half  new  sand 
is  tempered  and  the  side  pieces  faced  with  it.  Black  sand  is 
rammed  firmly  against  this  facing  until  a  height  of  about  six 
inches  below  the  top  of  the  casting  is  reached.  The  sides  of  the 
core  are  then  vented  and  two  channelways  of  cinders  are 
formed,  extending  the  length  of  the  green-sand  core  into  the 
body  of  sand  around  the  mold.  In  order  to  do  this,  the  joint 
must  be  broken  up  somewhat.  Pieces  of  pipe  are  placed  to 
bring  the  vent  from  the  cinder  beds  to  the  outside  of  the  mold 
as  described  in  Chapter  V.  The  cinders  used  should  be, 
roughly,  five-eighths  inch  diameter  and  should  not  come  closer 
than  four  inches  to  the  side  of  the  mold.  After  tamping  them 
with  the  rammer,  paper  is  placed  over  them,  it  also  being  kept 
back  four  inches  from  the  edge  of  the  mold.  Should  the  paper 
be  allowed  to  extend  to  the  edge,  iron  would  find  its  way  into 
the  sand  through  the  crack  formed  by  the  paper,  and  raise  the 
face  of  the  mold. 

The  sand  is  now  rammed  on  top  of  the  paper  to  within  a 
short  distance  of  the  top  of  the  side  pieces,  when  it  is  struck  off 
with  a  sweep  running  on  the  side  pieces.  These  latter  extend 
above  the  surface  so  that  the  sweeps  will  not  bear  on  the  joint 
when  used.  The  whole  surface  is  then  vented  down  to  the 
cinder  beds.  The  surface  of  the  mold  must  be  soft  enough  for 
the  gas  to  escape  easily  and  allow  the  melted  iron  to  lie  quietly 
on  it.  The  casting  being  very  thin,  will  be  scabbed  and  in- 
jured should  the  iron  boil  while  covering  this  green-sand  core. 
Making  the  face  of  this  core  is  usually  done  by  hand.  In  order 


68  FOUNDRY    PRACTICE 

to  form  it  to  the  proper  height  to  give  the  correct  thickness, 
the  sweep  G  is  first  used.  The  first  sweep  used  left  the  sand 
about  three-quarters  of  an  inch  below  the  final  face  of  the  core. 
The  same  mixture  of  sand  which  was  used  to  face  the  inside  of 
the  side  pieces  is  now  used  to  make  up  the  upper  face  of  the 
center.  This  sand  is  pressed  lightly  down  in  place  by  hand 
or  it  is  thrown  in  handfuls  down  on  the  surface.  The  sweep 
G  is  then  used  to  true  the  sand  from  /  to  /,  Fig.  42.  At  point 
/,  a  recessed  panel  X  is  formed  and  sweep  H  is  used  to  sweep 
the  sand  out  to  a  greater  depth  at  the  center  of  the  core,  where 
this  panel  is  to  come.  This  sweep  is  used  from  J  to  K  after 
which  the  sweep  G  is  used  to  complete  the  surface  from  K  to 
M.  The  top  of  the  center  is  now  finished  and  the  side  pieces 
drawn,  fillets  first  being  formed  on  the  edges.  The  mold  is 
then  blackened  over  its  entire  surface,  except  at  the  center, 
with  plumbago.  A  slight  coating  of  talc  is  then  dusted  over 
the  entire  surface  to  assist  the  flow  of  iron  through  the  mold. 
Gates  are  next  cut  for  pouring,  being  shown  by  the  dotted 
lines  R,  Fig.  42,  and  also  gates  to  the  risers.  Flour  or  white 
sand  is  placed  on  the  joint  and  the  cope  is  lowered  into  position. 
The  cope  is  then  raised  and  the  mold  examined  to  see  if  the 
cope  bears  solidly  as  will  be  evidenced  by  marks  in  the  white 
sand  or  flour,  necessary  repairs  are  made,  pouring  basins  and 
heads  or  flow-offs  from  risers  are  built,  and  the  cope  is  lowered 
into  place.  The  cope  may  be  secured  either  by  means  of 
binders  as  described  in  Chapter  V,  or  it  may  be  weighted 
down.  Iron  for  a  casting  of  this  character  must  be  poured 
sharp,  that  is,  extremely  hot. 

A  point  which  has  been  omitted  in  the  description  of  the 
making  of  the  mold  is  the  provision  of  a  camber  in  the  pattern 
in  order  that  the  casting  shall  come  straight  when  cooled.  As 
the  sides  of  the  casting  are  thin,  when  the  melted  iron  is  poured 
the  lower  part  of  the  thin  side  fills  quickly  and  sets  hard  before 
the  top  of  the  casting  is  set.  This  almost  instant  cooling  of 
the  sides,  combined  with  the  later  cooling  of  the  top,  causes  the 
shrinkage  in  the  sides  and  top  to  be  unequal.  The  shrinkage 
of  the  top  tends  to  draw  the  ends  upward  and  thus  give  a  bent 


MOLDING  COLUMNS  69 

casting,  or  to  crack  the  casting  if  the  moulding  on  the  sides 
has  been  left  off  or  if  the  iron  is  not  especially  soft.  If  the  sides 
are  heavier  than  the  plate  forming  the  top  of  the  casting,  the 
casting  will  cool  at  about  the  same  rate  in  all  parts  and  thus 
avoid  bending.  There  are  one  or  two  methods  of  avoiding 
this  bending  of  the  casting.  One  is  to  make  the  pattern  with  a 
slight  camber  in  it,  the  ends  being  at  a  lower  level  than  the 
center.  Another  method  is  to  force  the  ends  of  the  pattern 
down  in  the  mold,  below  the  level  of  the  center,  so  that,  with 
either  method,  the  mold  itself  is  curved  in  the  opposite  direc- 
tion to  that  in  which  the  casting  would  curve  in  cooling.  The 
same  shrinkage  effects  will  occur  with  the  mold  made  in  this 
manner,  but  the  casting  originally  being  curved  in  the  opposite 
direction,  the  shrinkage  in  cooling  will  pull  it  straight. 

By  using  a  solid  pattern  and  ramming  it  up  to  get  the  ex- 
terior surface  first  and  then  making  the  center  by  means  of  side 
pieces  as  described,  the  pattern  is  easier  to  mold  and  castings 
of  the  desired  thickness  are  more  likely  to  be  obtained.  The 
side  pieces  should  be  provided  with  straps  and  eye-bolts  for 
drawing  them  out  of  the  sand  as  shown  in  the  illustration. 
There  is  but  little  chance  to  rap  them  while  drawing,  and  they 
are  usually  drawn  by  means  of  a  hook  in  the  eye-bolt,  the 
other  end  of  the  hook  being  attached  to  a  lever.  While  bearing 
down  on  the  lever,  the  hook  or  top  of  the  eye-bolt  is  rapped 
slightly. 

MOLDING  A  ROUND  COLUMN 

In  many  foundries  it  has  been  the  custom  to  use  split  pat- 
terns in  molding  round  columns,  drawing  one-half  of  the 
pattern  from  the  drag  and  the  other  from  the  cope.  Other 
foundrymen  prefer  to  use  the  solid  pattern.  In  molding,  the 
pattern  would  be  laid  in  a  frame,  the  drag  being  placed  on  top 
in  the  usual  manner,  rammed  up,  rolled  over,  and  the  joint 
made.  The  cope  would  then  be  rammed  up  and  the  pat- 
tern rapped  through  the  cope,  thus  avoiding  a  seam  showing 
on  the  casting.  Another  method  would  be  to  bed  the  pattern 
in  the  flopr,  if  only  a  few  were  to  be  made,  and  to  stake  the 


FOUNDRY    PRACTICE 


cope  in  position  as  in  molding  the  ornamental  column  described 
earlier  in  this  chapter.  Fig.  43  shows  a  column  pattern  placed 
on  a  board  as  described  with  the  drag  around  it  ready  to  be 
rammed  up  and  rolled  over. 

Round  columns  are  frequently  provided  with  brackets  to 
support  I-beams.     The  column  shown  in  Fig.  43  has  such  a 


!!  I!*!  I!  !!|lljkjL[LLLL]i|!| 


FlG.  44.   SIDE  VIEW  OF  MOLD    OF  COLUMN  WITH  BRACKETS  IN  COPE  AND  DRAG. 


IT  TT 

FIGS.  43-45. — MOLDING  COLUMNS. 

bracket  which  will  be  molded  in  the  drag,  while  Fig.  44  shows 
a  column  with  brackets  to  be  molded  in  both  cope  and  drag. 
This  latter  column  illustrates  some  special  devices  adopted  in 
molding.  For  instance,  it  will  be  noted  that  the  bracket  B 
extends  to  the  top  of  the  cope.  A  head  of  iron  of  greater  depth 
than  this  is  required  in  order  to  insure  the  filling  of  the  mold 
of  the  bracket.  To  make  the  cope  of  the  requisite  depth  re- 
quired to  provide  this  head,  and  also  to  provide  the  necessary 
thickness  of  sand  over  the  pattern,  would  entail  unnecessary 
expense  and  also  render  the  flask  more  difficult  to  handle.  It 


MOLDING   COLUMNS  71 

would  also  necessitate  a  greater  amount  of  time  to  ram  up 
the  deeper  cope.  In  order  to  avoid  these  features,  the  cope  is 
simply  boxed  over  at  the  bracket  and  at  each  end  of  the  flask 
where  the  pouring  gates  are  located. 

In  the  author's  opinion,  the  cheapest  manner  of  molding 
round  columns,  when  there  are  a  number  to  be  made,  is  to 
make  a  solid  pattern  and  use  a  drag  of  the  required  length, 
width,  and  depth.  The  drag  should  be  placed  on  the  molding- 
board  and  leveled  with  the  joint  side  up.  Sand  from  the  heap 
is  rammed  to  a  point  very  near  the  joint,  but  so  formed  as  to 
leave  a  trough  through  the  center.  The  sweep  F,  Fig.  45,  is 
then  used  and  the  sand  is  swept  out  to  a  depth  of  about  three- 
quarters  of  an  inch  greater  than  the  half  diameter  of  the  pat- 
tern. Facing  sand,  mixed  according  to  the  thickness  of  the 
column,  is  then  spread  on  the  surface  left  by  the  sweep  and 
the  sweep  G,  raised  from  the  joint  of  the  flask  about  one- 
quarter  inch,  is  used  to  form  the  facing  to  the  shape  of  the 
pattern.  The  pattern,  if  free  of  brackets,  is  then  laid  in  the 
trough  so  formed  and  rapped  down  until  the  block  of  wood  H, 
which  is  used  as  a  gauge,  rests  on  the  top  of  the  pattern  and  the 
joint  of  the  flask.  If  a  bracket  is  to  be  made  on  the  lower  side 
of  the  casting,  sand  is  dug  out  of  the  trough  where  the  bracket 
is  to  be  formed,  and  after  the  pattern  is  placed  in  position  and 
rapped  down,  facing  sand  is  laid  around  the  bracket  and  sand 
rammed  in  against  it  and  against  the  pattern  where  needed. 
The  same  gauge  that  was  used  to  set  the  pattern  is  now  used 
as  a  sweep  to  sweep  the  sand  from  each  side  of  the  pattern  at 
the  joint.  The  joint  is  vented,  after  which  the  cope  is  placed 
and  rammed  up  with  gate-sticks  and  risers  in  their  proper 
places.  The  pattern  is  rapped  through  the  cope,  a  gate-stick 
having  been  placed  over  a  hole  in  the  pattern,  provided  for  this 
purpose.  The  rapping  bar  is  entered  through  this  hole,  which, 
after  the  removal  of  the  bar,  is  filled  up.  The  cope  bracket  is 
pinned  to  the  cope  side  of  the  pattern  and  when  the  cope  is 
hoisted  off,  the  bracket  is  found  in  it.  In  ramming  up  the  cope, 
the  spaces  /  and  /  between  the  ends  of  the  flask  and  the  first 
bar  are  not  rammed  up.  The  gate-sticks  are  set  between  the 


72  FOUNDRY   PRACTICE   ' 

next  two  bars  as  at  K.  The  runner  boxes  D,  which  are  usually 
free  from  the  cope,  are  not  rammed  up  with  the  cope,  but  later 
after  the  mold  is  closed. 

After  the  cope  is  rammed  up,  it  is  rolled  over  and  the 
bracket  has  the  sand  secured  around  it,  usually  by  means  of 
spikes,  and  the  bracket  pattern  is  drawn.  It  is  frequently  ad- 
visable to  ram  a  dry-sand  core  in  the  mold  against  the  face  of 
the  bracket  which  is  to  be  used  as  a  seat  for  the  I-beam.  After 
the  pattern  is  drawn,  the  face  of  the  mold  is  felt  and  any  soft 
spots  filled  up  with  a  pipe  slicker.  The  cope  is  then  given  a 
coat  of  silver  lead  and  the  chaplets  for  holding  down  the  cores 
are  placed  as  described  in  Chapter  XIV.  The  joint  of  the  drag 
being  brushed  off,  a  channel  is  formed  alongside  the  drag  which 
is  dampened  with  the  bosh.  A  vent-wire  is  bent  and  run  from 
this  channel  under  the  pattern,  thus  venting  under  the  pat- 
tern and  alongside  of  it  to  the  side  of  the  flask.  As  the  sides 
were  previously  vented  toward  the  bottom-board,  before  the 
joint  was  made,  the  escape  of  gases  from  the  drag  is  thus  pro- 
vided for.  The  mold  is  now  finished  and  blacked. 

In  gating  round  columns,  the  gates  are  made  on  the  ends, 
alongside  the  core  on  both  sides  of  the  mold.  The  iron  fills 
the  column  poured  in  this  manner  with  slacker  iron  than  when 
the  mold  is  gated  along  the  sides.  The  mold  being  finished, 
the  core  is  calipered  and  also  the  pattern.  One-half  the  dif- 
ference in  diameter  between  the  two  is  the  distance  which 
chaplets  must  project  above  the  surface  of  the  mold  in  order 
to  support  the  cores  in  the  proper  position.  In  selecting  the 
chaplets,  it  should  be  remembered  that  with  a  large  body  of 
iron  flowing  into  the  mold,  a  much  larger  diameter  is  required 
than  for  smaller  cores.  For  a  thickness  of  casting  of  one  and 
one-half  inches  in  the  column,  we  would  use  a  chaplet  with  a 
stem  about  one-half  inch  diameter.  Using  a  lighter  chaplet 
will  probably  permit  the  core  to  settle  as  the  chaplet  would 
soften  under  the  influence  of  hot  iron  and  the  weight  of  the 
core  would  cause  it  to  crush  and  thus  permit  the  core  to  settle. 
On  the  other  hand,  chaplets  used  in  the  cope  must  be  stiff 
enough  to  withstand  the  pressure  of  the  core  being  floated 


MOLDING   COLUMNS  73 

upward  by  the  entering  iron.  The  chaplets  are  driven  clear 
through  the  drag,  into  the  bottom-board,  which  they  should 
enter  for  a  distance  of  about  three-eighths  of  an  inch.  The 
number  of  chaplets  to  be  placed  in  the  cope  and  drag  depends 
on  the  size  and  general  arrangement  of  the  cores.  No  fixed 
rule  can  be  given  except  that  it  is  better  to  have  too  many 
rather  than  too  few  chaplets. 

It  is  much  easier  with  a  long  column,  to  make  and  set  the 
core  in  two  pieces  rather  than  in  one.  The  cores  are  butted 
together  at  the  center  of  the  mold,  one  end  resting  in  a  core- 
print  at  either  end,  the  other  end  of  each  piece  being  supported 
at  the  middle  of  the  mold  by  chaplets.  To  prevent  'the  cores 
shifting  sidewise,  due  to  iron  entering  one  side  of  the  mold 
more  rapidly  than  the  other,  chaplets  are  placed  on  either 
side  of  the  cores  at  the  ends  where  they  are  butted  together. 
These  chaplets  are  wedged  in  place  by  a  wedge  driven  between 
the  end  of  the  chaplet  and  the  side  of  the  flask.  After  placing 
the  chaplets,  flour  or  sand  is  arranged  on  the  joint  to  afford  a 
tell-tale  as  to  whether  the  cope  bears  on  the  cores  or  on  the 
joint.  In  the  ends  of  the  flask  at  the  joint  are  holes  through 
which  are  shoved  short  rods  into  the  vent  holes  in  the  end  of 
the  column  cores,  as  shown  at  0,  Fig.  44.  Sand  is  then  rammed 
in  the  spaces  /  and  /,  after  which  the  rod  O  is  removed,  leaving 
a  clear  hole  from  the  vent  of  the  core  to  the  outside  of  the  mold. 
Two  or  more  vent  holes  are  sometines  left  in  the  core,  depend- 
ing on  its  size,  and  as  many  vent  rods  are  used  as  there  are 
holes  in  the  core.  It  is  advisable  to  put  a  little  paste  on  the 
ends  of  the  cores  before  closing  the  mold  in  order  to  exclude 
iron  which  might  find  its  way  over  the  cores  and  thus  stop 
the  vent  hole. 

The  pouring  boxes  D  and  E  are  next  placed  and  pouring 
basins  P  built.  These  boxes  are  fastened  by  driving  a  nail  a 
short  distance  into  the  cope.  In  securing  the  cope,  clamps  are 
used  and  binders  are  placed  to  hold  the  core  down  through 
the  agency  of  the  chaplets,  wedges  being  driven  between  the 
ends  of  the  chaplets  and  the  binders  which  are  clamped  across 
the  top  of  the  flask. 


74  FOUNDRY    PRACTICE 

The  iron  used  in  pouring  should  be  cooled  until  it  is  quite 
dull  for  the  larger  and  thicker  columns,  and  it  is  advisable  to 
feed  the  larger  sizes  of  columns  through  the  riser  on  the  bracket 
to  avoid  shrinkage.  Columns  seldom  shrink  the  full  allowance 
— one-eighth  inch  to  the  foot — and  for  that  reason  column 
patterns  are  usually  made  with  a  smaller  shrinkage  allowance. 
It  is  important  that  the  same  iron  mixture  be  used  in  pouring 
all  the  columns  of  a  given  lot,  particularly  ornamental 
columns;  otherwise  there  will  be  a  difference  in  the  shrinkage, 
resulting  in  columns  of  varying  lengths. 

When  molding  columns  of  the  following  approximate  di- 
mensions— fourteen  feet  long,  six  inches  wide,  and  sixteen 
inches  deep,  with  a  thickness  of  one-half  to  five-eighths  inch 
— it  is  best  to  mold  them  on  edge  to  avoid  troubles  due  to 
the  shrinkage  curving  the  column  in  cooling.  In  many  cases, 
castings  with  heavy  parts  must  have  these  parts  uncovered 
in  order  to  permit  them  cooling  more  rapidly.  The  entire 
casting  is  then  cooled  more  nearly  at  a  uniform  rate  and 
warping  is  thereby  avoided. 

The  pattern  for  a  fluted  column  is  usually  made  in  quarters, 
and  the  two  quarters  of  each  half  are  hinged  together,  where  a 
space  comes  between  the  flute  and  the  out- 
side, as  shown  in  Fig.  46.  A  piece  of  flat  iron 
is  let  into  the  joint  side  to  hold  the  quarters 
apart  and  in  this  way  form  one-half  of  the 
pattern.  The  two  halves  are  pinned  together. 

TERNFOR  A  FLUTED  In  moldmg» the  coPe  and  drag  are  molded  as 
COLUMN.  a  plain  pattern.  To  draw  the  pattern,  the 

screws  holding  the  pieces  of  flat  iron  in  place  are  removed 
and  the  two  quarters  closed  together,  sufficient  material  being 
cut  away  from  each  quarter  to  form  a  V-shaped  opening  the 
entire  length  of  each  half  of  the  pattern.  After  closing  together 
the  pattern  can  be  lifted  out  of  the  mold. 

The  method  of  making  cores  for  columns  is  described  in 
Chapter  XIII. 


CHAPTER  VII 

MOLDING  WITH  SWEEPS 

THE  expense  of  pattern  work  for  certain  classes  of  castings 
of  a  regular  form  may  be  avoided  by  the  use  of  a  sweep.  Such 
castings  as  circular  boiler  fronts,  tank  heads,  pulley  rims,  and 
similarly  shaped  castings  can  easily  be  molded  by  this  method. 
In  addition,  certain  irregular-shaped  castings  may  be  partially 
swept  out  in  green-sand  molds,  the  balance  of  the  mold  being 
finished  by  means  of  pattern  pieces.  The  sweep  consists  of  a 
board,  one  edge  of  which  is  shaped  to  correspond  with  the 
surface  of  the  casting  and,  on  drawing  it  across  the  sand,  it 
leaves  a  surface  in  the  mold  of  the  desired  shape  to  make  the 
casting. 

In  Figs.  47-50,  the  method  of  molding  a  ribbed  tank  cover, 
by  means  of  sweeps,  is  illustrated.  The  casting  is  a  circular 
piece  of  dished  cross-section  with  four  ears,  slotted  to  receive 
bolts,  placed  at  equal  intervals  around  its  circumference.  In 
molding  it,  two  or  three  sweeps  are  used,  according  to  the  ideas 
of  the  molder,  and  no  pattern  work  is  necessary  excepting  for 
the  four  ears  and  for  the  ribs  on  the  under  side  of  the  dished 
portion. 

In  making  the  mold  for  this  casting,  the  first  operation  is 
to  set  the  spindle  seat  in  the  floor.  The  spindle  seat  consists 
of  a  socket  for  the  spindle  of  the  sweep,  and  is  mounted  on 
four  cross  arms,  extending  horizontally  from  the  body  of  the 
socket.  A  hole  is  dug  in  the  floor  of  such  depth  that  the  top  of 
the  spindle  seat  will  come  level  with  the  floor  line  when  the 
spindle  seat  is  leveled  in  it.  The  spindle  is  placed  in  the  seat 
and  by  means  of  spirit  level  is  plumbed  until  it  is  truly  vertical, 
wedges  being  driven  under  one  leg  or  the  other  of  the  spindle 
seat,  to  throw  the  spindle  in  the  necessary  direction  to  bring  it 
vertical.  Sand  is  then  rammed  around  the  spindle  seat  until 
75 


76  FOUNDRY   PRACTICE 

the  hole  in  the  floor  is  filled.  The  sand  around  the  spindle  is 
then  swept  off  level  by  means  of  the  sweep.  This  is  a  plain 
piece  of  board  about  four  inches  wide  and  of  any  desired  length 
and  with  a  beveled  lower  edge.  Attached  to  one  end,  by  means 
of  bolts,  is  a  finger  which  fits  snugly  over  the  spindle,  being 


FIG. 48  SETTING  SPINDLE  SEAT 

FIGS.  47-50. — SWEEPING  A  RIBBED  COVER  PLATE  MOLD. 


fastened  thereto,  and  permits  the  sweep  and  the  spindle  to 
be  revolved.  The  sand  being  rammed  down  around  the 
spindle,  the  sweep  is  revolved  and  sweeps  off  any  surplus 
sand,  leaving  a  level  and  true  bed  of  sand. 

The  sweep  finger  is  then  removed  from  the  spindle  and  a 
bottom-board  with  a  hole  in  the  center,  lowered  over  the 


MOLDING   WITH    SWEEPS  77 

spindle,  or  the  spindle  may  be  removed  from  the  seat,  the 
bottom-board  placed  in  position,  and  the  spindle  re-inserted 
in  the  seat  through  the  hole  in  the  bottom-board.  The  drag  of 
the  flask  is  then  placed  on  the  bottom-board  with  the  joint  up 
and  is  wedged  up  a  short  distance  by  means  of  wedges  set  from 
the  inside  of  the  flask.  The  sweep  for  forming  the  cope  side  of 
the  mold  is  bolted  to  the  sweep  finger  and  leveled.  The  end 
of  the  sweep  is  allowed  to  rest  on  a  trowel  laid  on  the  joint  of 
the  drag  while  it  is  being  leveled  so  that  on  removing  the 
trowel,  the  sweep  has  a  clearance  from  the  drag  of  the  thickness 
of  the  trowel.  In  certain  cases  a  guard  is  placed  around  the 
spindle  to  prevent  sand  from  passing  through  the  hole  in  the 
bottom-board.  Such  a  guard  is  shown  at  G. 

Cinders  are  next  spread  over  the  bottom-board  and  covered 
with  paper,  after  which  the  drag  is  rammed  full  of  sand.  When 
it  has  reached  the  proper  height,  the  sweep  is  revolved,  tracing 
in  the  sand  a  circular  cavity  of  the  exact  shape  of  the  bottom 
of  the  sweep.  The  sand  should  be  rammed  in  the  drag  as  hard 
as  possible  preparatory  to  this  operation.  When  it  has  been 
struck  off,  after  sweeping,  it  is  slicked  and  parting  sand  is 
dusted  over  the  joint,  and  sometimes  over  the  face  formed  by 
the  sweep.  Instead  of  parting  sand,  paper  is  sometimes  laid 
over  the  swept  surface,  being  first  wet  in  order  to  make  it  con- 
form to  the  exact  shape  of  the  mold.  The  use  of  paper  makes 
a  very  clean  parting,  whereas,  if  parting  sand  is  dusted  on,  it 
must  later  be  brushed  off  which  not  only  tends  to  make  a  rough 
surface  on  the  casting,  but,  if  not  thoroughly  removed,  is  liable 
to  be  washed  off  when  the  casting  is  poured  and  make  dirt  in 
the  casting. 

The  ribs  which  are  to  be  cast  in  the  cope  and  for  which 
patterns  are  required,  are  placed  as  shown  at  /  in  the  plan  of 
the  cope,  Fig.  50,  being  held  in  place  by  a  few  nails  pushed  into 
the  sand  alongside  of  them.  The  spindle  is  then  removed  and 
the  green-sand  core  /  having  been  formed,  a  bunch  of  waste  is 
placed  in  the  hole  left  by  the  spindle.  The  cope  of  the  flask  is 
then  placed  in  position,  gaggers  set,  and  the  cope  rammed  up  as 
for  any  ordinary  mold,  the  patterns  for  the  ears  first  being 


78  FOUNDRY    PRACTICE 

placed  in  position.  After  venting,  the  cope  is  turned  over,  the 
ribs  and  ear  patterns  drawn,  and  the  edges,  where  the  ribs 
unite  with  the  body  of  the  casting,  filleted.  The  gates  are 
prepared  as  desired  and  the  cope  is  blackened  with  plumbago. 

The  next  operation  is  to  sweep  out  the  drag.  It  will  be 
remembered  that  in  sweeping  out  the  drag  first,  what  was 
known  as  the  cope  sweep  was  used.  This  was  for  the  purpose 
of  forming  a  recess  the  exact  size  of  the  projection  of  sand 
desired  in  the  cope.  In  order  to  give  thickness  to  the  casting, 
the  drag  must  be  swept  out  to  a  greater  depth  than  was  done 
by  the  cope  sweep.  The  drag  sweep  used  is  of  exactly  the  same 
shape  as  the  cope  sweep,  but  is  as  much  deeper  than  it  as  the 
casting  is  thick.  The  drag  sweep  is  bolted  to  the  sweep  finger, 
the  sand  is  dug  out  from  over  the  bunch  of  waste,  and  the  waste 
removed  from  the  spindle  hole,  after  which  the  spindle  is  set.  A 
gutter  is  dug  from  the  spindle  to  the  outside  of  the  flask  of  suffi- 
cient depth  to  permit  the  sweep  to  rest  on  the  trowel  on  the 
joint.  The  sand  is  dug  up  to  about  three-quarters  inch  below 
the  edge  of  the  sweep,  the  sweep  is  revolved,  and  the  surplus 
sand  removed.  The  drag  is  thoroughly  vented  down  to  the 
cinder  bed,  after  which  facing  sand,  properly  tempered  and 
riddled,  is  thrown,  a  handful  at  a  time,  on  the  face  of  the  mold 
where  it  will  stick.  The  entire  face  of  the  mold  is  covered  in 
this  manner,  the  sweep  being  revolved  as  the  sand  is  thrown, 
in  order  to  form  a  surface  of  the  desired  shape.  The  face  is 
examined  for  soft  spots  which  are  repaired  as  found  and  the 
spindle  is  removed.  The  mold  is  finished,  blackened,  gated, 
and  made  ready  for  pouring  in  exactly  the  same  manner  as 
any  other  mold. 

It  may  be  well  at  this  point  to  call  attention  to  some  things 
that  should  be  borne  in  mind  in  sweeping  molds.  We  have  de- 
scribed above  the  method  of  sweeping  a  comparatively  light 
casting.  If  instead  the  casting  should  weigh  several  tons 
rather  than  a  couple  of  hundred  pounds,  the  operations  of 
molding  would  be  the  same,  but  the  greater  amount  of  metal 
would  bring  considerably  greater  strain  on  the  face  of  the  mold, 
particularly  on  the  drag,  and  certain  precautions  must  be  ob- 


MOLDING   WITH    SWEEPS  79 

served  to  take  care  of  this.  After  ramming  up  the  cope  as 
above  described,  the  drag  would  be  dug  out  in  the  same  manner 
as  for  the  lighter  casting.  The  sweep  is  made  so  that  it  can  be 
lowered  three-quarters  of  an  inch  below  what  is  to  be  the  face 
of  the  mold  or  a  third  sweep  is  made,  which  will  sweep  out  the 
sand  to  this  depth.  After  digging  out  the  sand  from  the  drag, 
in  the  manner  described,  black  sand  is  solidly  rammed  on  the 
face  to  the  line  of  this  third  sweep  or  to  the  edge  of  the  sweep 
lowered  below  the  level  of  the  face.  The  surface  thus  formed  is 
thoroughly  vented,  after  which  facing  sand  is  thrown  on  as 
was  done  for  the  lighter  casting,  and  the  face  of  the  mold  is 
finally  finished. 

The  object  of  using  this  third  sweep  or  its  equivalent,  and 
making  a  solid  face  on  which  facing  sand  is  built,  is  to  provide 
an  evenly  rammed  surface  for  the  mold.  If  there  is  any  dif- 
ference in  the  strength  of  the  mold,  in  different  portions,  the 
casting  will  be  distorted.  If  the  hard-rammed  sand  is  left 
uneven  when  digging  off  the  face  and  the  facing  sand  simply 
thrown  down  on  it  as  described,  the  molten  iron  filling  the  mold 
will  soon  discover  the  point  at  which  this  facing  sand  is  the 
deepest  and  at  this  spot  will  cause  the  sand  to  give.  In  other 
places,  where  the  sand  was  not  cut  away  to  the  same  depth, 
the  facing  will  be  harder  and,  therefore,  the  surface  of  the  cast- 
ing will  be  found  to  be  uneven,  being  at  the  proper  level  over 
the  hard  portions  and  having  projections  at  those  points  where 
the  facing  sand  was  deepest  and  therefore  soft.  It  is  evident, 
therefore,  that  by  ramming  the  surface  at  a  depth  of  three- 
quarters  of  an  inch  below  the  face  of  the  mold,  and  then 
building  the  face  of  the  mold  on  this  surface,  the  pressure  of  the 
molten  metal  is  resisted  evenly  over  the  entire  surface  of  the 
mold  and  a  casting  with  a  true  surface  is  the  result.  The  lack 
of  care  in  making  this  firm  under-surface,  is  often  responsible 
for  the  failure  to  obtain  good  results  with  swept  up  molds. 

Oftentimes,  patterns  molded  by  bedding  them  in  the  floor 
or  a  flask,  may  have  a  portion  of  the  mold  made  by  a  sweep 
and  the  balance  made  by  placing  the  pattern  on  it  and  tucking 
the  sand  under  those  parts  of  the  pattern  which  are  irregular 


80  FOUNDRY   PRACTICE 

in  shape.  In  this  way,  the  pounding  of  the  pattern  into  the 
bed  is  avoided.  To  illustrate  this  method  of  molding,  we  will 
consider  the  case  of  a  tank  bottom,  eight  feet  long,  five  feet 
wide,  and  five-eighths  inch  thick,  which  is  to  be  bedded  in  a 
flask.  A  bed  of  sand  is  first  made  on  the  floor  where  the  center 
of  the  flask  will  rest,  being  made  one  foot  wide  and  a  trifle 
longer  than  the  flask.  This  is  made  three  inch  thick  and  is 
trodden  down  firmly  and  is  struck  off  with  a  straight  edge. 
On  this  a  bottom-board  is  placed  and  the  drag  set,  being 
raised  about  five-eighths  of  an  inch  from  the  bottom-board  by 
means  of  wedges  driven  between  them  from  the  inside  of  the 
flask.  The  bottom-board  is  then  wedged  up  on  one  side  until 
it  has  an  inclination  of  about  five-sixteenths  inch  in  two  feet. 
Cinders  are  next  spread  over  the  surface  of  the  bottom-board 
and  covered  with  paper,  after  which  straight-edges  G,  Figs. 
51  and  52,  are  placed  and  raised  to  the  desired  height  by  means 
of  bricks  and  wedges  H,  or  they  may  be  made  of  sufficient 
depth  to  rest  directly  on  the  bottom-board.  They  are  leveled 
and  secured  at  the  desired  height  and  sand  rammed  in  around 
them  to  prevent  their  movement  sideways.  Black  sand  is 
then  rammed  over  the  cinders  until  it  is  about  level  with  the 
top  of  the  straight-edges.  The  sweep  /  is  used  with  the  notched 
side  down,  the  bottom  of  the  sweep  being  notched  so  that 
the  edge  /  is  five-eighths  inch  below  the  edge  of  the  straight- 
edge, to  sweep  out  the  sand  between  the  straight-edges  to  that 
depth.  The  bed  of  sand  is  then  thoroughly  vented  down  to 
the  cinder  bed,  after  which  a  mixture  of  seacoal  facing,  in  the 
ratio  of  one  seacoal  and  fourteen  sand,  thoroughly  tempered 
and  riddled,  is  spread  on  the  bed  between  the  straight-edges, 
until  its  surface  is  slightly  above  the  straight-edge.  The  sweep 
with  the  straight  side  down  is  then  used,  a  block  of  wood  one- 
eighth  inch  thick  being  placed  under 'each  edge,  and  the  sand 
swept  level.  The  blocks  are  removed,  and  one  man  holding  an 
end  of  the  sweep  on  the  straight-edge,  a  man  on  the  other  end 
strikes  the  straight-edge  a  blow  with  the  opposite  end.  The 
sweep  is  moved  gradually  across  the  width  of  the  mold,  the 
sand  being  pounded  down  in  this  way,  first  by  the  man  at  one 


MOLDING  WITH   SWEEPS  8 1 

end  and  then  by  the  man  at  the  other.  This  process  will  ram 
the  sand  solidly,  and  a  casting  weighing  many  tons  can  be 
poured  on  it  without  danger  of  rough  spots  being  formed,  due 
to  soft  places  in  the  mold.  The  bed  being  made,  the  pattern 
is  placed  on  it,  weighted  down,  and  sand  rammed  around  the 
edges.  The  joint  is  made  and  the  cope  rammed  up,  the  gates 
being  set  so  that  hot  iron  shall  flow  into  the  mold  up  to  the 
last  moment  of  pouring. 

It  will  be  recollected  that,  at  the  beginning  of  operations, 
we  wedged  the  bottom-board  so  that  one  side  of  the  flask  was 
higher  than  the  other.  This  was  done  so  that  the  iron,  in 


FIGS.  51-52. — MOLDING  A  TANK  COVER  PLATE  WITH  A  SWEEP. 

pouring,  would  fill  the  lower  side  of  the  mold  first  and  rise 
along  the  face  of  the  mold  as  it  fills.  If  the  mold  were  to  be 
level,  the  iron  would  cover  the  entire  lower  surface  of  the  mold 
before  it  reached  the  upper  surface.  The  lower  portion  of  the 
mold  would  require  covering  with  liquid  iron  immediately  or 
cold  shuts  would  result  which  might  ruin  the  casting.  By 
causing  the  iron  to  flow  into  the  mold  from  the  higher  side,  this 
trouble  will  be  avoided  and  a  slacker  iron  can  be  used.  A  slight 
coating  of  talc  over  the  entire  face  of  the  mold  will  assist  in  the 
rapid  flow  of  the  iron. 

We  will  now  consider  the  case  of  a  pattern  which  is  to  be 
molded  in  part  with  a  sweep  and  the  remainder  tucked  up. 
Referring  to  Fig.  53,  the  method  of  molding  the  face  of  the 
6 


82 


FOUNDRY   PRACTICE 


segment  of  a  large  built-up  fly-wheel  is  shown.  In  molding 
these  segments,  it  is  desired  to  have  the  face  as  nearly  as 
possible  on  the  same  circle  as  the  finished  wheel,  leaving  merely 
enough  stock  for  finishing.  Two  cast-iron  guides  A  are  ar- 
ranged to  rest  on  timbers  -B  in  the  flask  and  using  a  similar 
sweep  to  that  described  in  the  operation  of  making  the  tank 


FIG.  53. — MOLDING  SEGMENT  OF  BUILT-UP  FLY-WHEEL. 

bottom,  a  bed  is  made  on  which  the  pattern  is  to  rest,  the  sweep 
being  guided  by  the  guides  A.  After  the  bed  is  made,  it  is 
vented  to  the  cinder  bed  which  has  previously  been  made  at 
the  bottom  of  the  flask  and,  on  top  of  this  bed,  a  face  is  built 
of  facing  sand  on  which  the  pattern  is  placed.  In  gating 
this  mold,  the  pouring  gates  must  be  further  apart  for  large- 
diameter  wheels,  say  thirty  feet,  than  for  smaller  wheels  of 

/F 


FIG.  54. — MOLDING  A  FORMER  FOR  SHEET-METAL  WORK  WITHOUT  A 
PATTERN. 


ten  or  fifteen  feet  diameter.  With  the  smaller  wheels,  the  iron 
flowing  in  and  being  given  a  quick  turn  due  to  the  smaller  di- 
ameter, will  be  given  a  whirling  motion  and  will  thereby  cut  the 
face  of  the  mold,  producing  a  scabbed  casting,  unless  the  mold 
is  of  the  proper  hardness. 

Fig.  54  shows  the  method  of  making  the  mold,  known  as 
a  former  for  sheet-metal  work,  without  a  pattern.  Two  boards 


MOLDING  WITH   SWEEPS  83 

with  the  size  of  the  inside  of  the  former  cut  in  them  as  shown  at 
A  are  set  in  ends  of  the  flask  and  sand  rammed  firmly  between 
them  and  swept  off  level  with  the  top  of  the  inside  of  the  guides 
A .  The  pieces  F,  shown  by  the  cross-hatching,  that  were  sawed 
out  from  the  guides  along  the  line  A ,  are  then  replaced  and 
sand  rammed  between  these  pieces  and  the  ends  of  the  flask. 
Damp  parting  sand  is  slicked  on  to  the  steeper  parts  of  the 
face  of  the  mold  and  dry  sand  dusted  on  the  flat  portion.  The 
cope  is  now  placed  on  the  drag  and  rammed  up  and  removed. 
The  end  pieces  F  are  now  removed  and  the  sand  dug  out  be- 
tween the  guides.  A  sweep  notched  somewhat  deeper  than 
the  thickness  of  casting  desired  as  shown  by  the  distance 
between  the  lines  A  D  is  used  to  strike  the  sand  off  along  the 
line  D,  the  sand  being  firmly  rammed  and  vented.  The  face 
of  the  mold  is  built  up  to  the  line  B,  a  sweep  notched  a 
distance  equal  to  AB  being  used.  The  mold  is  finished  and 
gated  in  the  usual  manner. 


CHAPTER  VIII 

MOLDING  CAR-WHEELS 

CAST-IRON  car-wheels  having  a  chilled  tread  are  cast  in 
molds  formed  partly  of  molding  sand  and  partly  of  cast-iron. 
The  pattern  used  in  forming  the  mold  is  what  is  termed  a  solid 
pattern,  being  made  in  one  piece  and  having  on  it  core-prints. 

The  flask  in  which  the  wheel  is  molded  and  cast  consists 
of  three  parts:  The  drag  in  which  the  flange  side  of  the 
wheel  is  molded,  the  wheel  being  poured  flange  side  down; 
on  top  of  the  drag,  a  cheek  or  chill  of  cast-iron  is  placed  to 
form  the  tread  and  part  of  the  flange;  on  top  of  the  chill 
rests  the  cope  in  which  the  face  of  the  wheel  is  molded. 
Over  the  center  of  this  is  a  raised  part  in  which  the  pouring 
basin  is  built.  The  flask  rests  on  a  perforated  iron  bottom- 
board  through  which  the  gases  escape  from  the  drag.  The 
entire  flask  is  of  cast-iron  and  the  cope  is  provided  with  radial 
bars  of  the  shape  of  pattern  to  hold  the  sand  in  the  cope. 
The  cast-iron  chill  is  chambered  and  connected  to  a  water 
supply  for  cooling  the  chill  if  required.  The  raised  part  of  the 
cope  is  provided  with  ears  to  take  the  tops  of  chaplets  which 
hold  down  the  lightening  cores  around  the  hub  of  the  wheel. 

Oftentimes,  before  the  wheels  are  molded  the  chill  part  of 
the  flask  is  oiled  in  order  to  prevent  it  sweating,  or  gathering 
dampness  from  the  warm  sand.  If  this  is  carelessly  done,  or  if 
the  chill  is  warm,  the  oil  may  find  its  way  to  the  bottom  of  the 
chill,  leaving  dry  spots  on  the  face  on  which  moisture  may 
condense  and  thus  crack  or  make  a  bad  place  on  the  tread  of 
the  wheel.  To  avoid  this,  sometimes  lead  is  mixed  with  the 
oil,  or,  instead  of  oil,  lampblack  and  shellac  are  mixed,  first 
killing  the  lampblack  with  alcohol.  The  chills  are  coated  with 
this  mixture,  as  one  would  black  a  pattern. 

In  molding,  the  pattern  is  placed  in  the  chill  portion  of  the 
84 


MOLDING   CAR-WHEELS  85 

flask  with  the  flange  side  up,  the  face  of  the  wheel  sliding  down 
in  the  chill  a  distance  equal  to  the  width  of  the  tread.  The 
flange  of  the  wheel  rests  in  a  part  of  the  chill  which  is  formed 
to  receive  it.  The  drag  is  placed  over  the  chill  and  the  pattern 
is  covered  with  a  mixture  of  facing  sand,  consisting  of  ten 
parts  of  old  molding  sand  from  the  heap,  two  parts  of  new 
molding  sand,  and  one  part  seacoal.  This  mixture  is  riddled 
into  the  drag  through  a  number  six  sieve,  and  the  facing  is 
laid  up  against  the  ribs  and  evened  off  to  a  depth  of  five- 
eighths  inch  over  the  pattern.  The  drag  is  then  shoveled  full 
of  sand  and  peened  around  the  edge  of  the  flask,  trodden  over 
and  butted  off.  The  sand  is  next  struck  off  flush  with  the  top 
of  the  drag  and  about  three-quarters  of  an  inch  of  loose 
molding  sand  is  thrown  over  the  drag,  after  which  it  is  vented 
and  the  bottom-board  rubbed  to  a  bearing.  The  bottom-board 
is  then  clamped  to  the  flask  and  by  means  of  a  yoke,  which 
is  hooked  to  the  trunnions  on  the  chill,  the  flask  is  raised  and 
rolled  over.  It  is  then  lowered  on  to  two  rails.  Care  should  be 
taken  that  these  rails  are  level  and  at  the  same  height,  as  it  is 
important  that  a  car-wheel  mold  should  fill  evenly  with  iron 
in  order  to  avoid  the  chill  cracking  the  wheel. 

After  the  gate-sticks  are  set  to  form  pouring  gates,  facing 
sand  is  riddled  over  the  pattern  and  heap  sand  is  shoveled  in 
until  the  cope  is  filled  flush  with  the  tops  of  the  bars.  The  sand 
is  then  peened  between  the  bars,  after  which  the  cope  is  heaped 
full  of  sand  which  is  trodden  down  and  then  butted  off.  The 
pouring  basin  is  built  and  the  sand  scraped  from  above  the 
bars  of  the  cope,  and  the  cope  is  vented  all  over  and  the  gate- 
sticks  removed.  Cope  and  chill  are  then  bolted  together  and 
hoisted  by  means  of  the  yoke,  leaving  the  pattern  in  the  drag. 

The  cope  is  finished,  blackened  with  silver  lead,  and  the 
chaplets  set  to  hold  down  the  ring  or  lightening  core.  The  chill 
is  given  a  coating  of  lard  oil,  or  of  shellac  and  lampblack,  or 
some  one  of  the  various  mixtures  made  for  application  to  chills. 
The  pattern  is  then  drawn  from  the  drag,  which  is  finished 
and  blackened  with  silver  lead,  and  a  vent- wire  is  run  down 
through  the  core-prints  to  the  bottom-board,  after  which  one 


86 


FOUNDRY   PRACTICE 


of  the  ring  cores  shown  in  Fig.  55  is  placed  with  the  three  pro- 
jections in  the  prints  in  the  drag.  The  center  core  is  next  set. 
Usually  the  sand  is  first  cut  up  to  form  a  ring  around  the  vent 
hole  so  that  the  core  may  press  down  on  it  and  thus  prevent  the 
iron  from  running  under  the  core  into  the  vent  hole.  Before 


TOP  OF  MOLD 


SIDE  OF  MOLD 
FIG.  55. — CAR-WHEEL  MOLD  AND  CHILL. 

setting  the  core,  a  vent  is  made  through  the  drag  to  the  bot- 
tom-board. 

The  cope  and  chill  are  next  rolled  over  on  the  trunnions  and 
lowered,  chill  down,  on  the  drag,  and  the  parts  of  the  flask 
are  clamped  together.  After  the  cope  is  closed,  the  chaplets 
are  moved  up  and  down  to  see  that  they  bear  properly  on  the 
top  of  the  core  they  are  to  hold  down.  A  wedge  is  placed 
between  the  top  of  the  chaplet  and  the  pouring  basin  part  of 
the  cope. 


MOLDING   CAR- WHEELS  87 

After  the  wheels  are  poured,  they  are  allowed  to  stand, 
usually  until  the  molder  has  poured  six,  after  which  they  are 
shaken  out  of  the  mold,  hoisted  out  of  the  sand  by  grasping 
the  rim  of  the  wheel  with  a  pair  of  tongs,  and  the  wheel  is 
moved  by  a  hot-wheel  train  to  the  annealing  pits.  The  heads 
are  broken  off  with  a  ram  and  the  center  cores  taken  out.  A 
crane,  arranged  to  handle  two  wheels  at  a  time  by  means  of 
two  pair  of  tongs,  grasps  the  wheels  in  the  center  and  moves 
them  over  the  proper  annealing  pit  in  which  sixteen  wheels 
are  placed  at  one  time  and  annealed  by  their  own  heat.  The 
wheels  remain  in  the  pit  four  days,  being  taken  out  on  the 
fifth  day. 

In  pouring  car-wheel  molds,  the  iron  can  be  poured  either 
too  hot  or  too  cold  and  it  is  necessary  that  the  mold  fill  evenly, 
otherwise  chill  cracks  may  result.  Pouring  the  iron  too  hot 
will  cause  a  variation  in  the  depth  of  chill  and  it  will  also  cause 
internal  strains  which  are  lessened  or  partly  avoided  when 
the  iron  is  poured  at  the  proper  temperature,  which,  however, 
can  only  be  learned  by  experience.  The  iron  poured  into  the 
mold  and  running  against  the  face  of  the  chill  is  hardened  on 
the  tread  of  the  wheel  by  being  cooled  rapidly,  producing,  as  we 
find  on  breaking  the  wheel,  a  hard  white  surface  which  is  about 
three-quarters  of  an  inch  deep,  becoming  mottled  toward  the 
inside.  From  the  mottling,  what  are  called  legs  or  veins, 
extend  into  the  gray-iron  portion  of  the  casting. 

While  the  pig  iron  used  in  the  manufacture  of  car-wheels 
is  usually  number  three,  or  three  and  one-half  charcoal  iron, 
mixed  with  a  certain  percentage  of  old  car-wheels,  occasionally 
steel  scrap  or  coke  iron  is  introduced  in  the  mixture.  The 
Chicago*  Milwaukee  and  St.  Paul  Railroad  adds  one  pound 
of  eighty  per  cent  ferromanganese  to  the  quantity  of  iron 
required  to  pour  one  wheel,  in  order  to  deepen  and  toughen 
the  chill.  This  is  added  to  the  iron  in  the  pouring  ladle. 

In  the  past  it  has  been  considered  that  the  greater  the 
amount  of  coke  iron  used  in  the  mixture,  the  more  distinct 
was  the  line  of  demarkation  between  the  chill  and  the  gray 
iron  in  the  casting.  The  wheel  in  running  would  constantly 


88  FOUNDRY   PRACTICE 

strike  on  one  spot  in  passing  from  rail  to  rail  and  the  shock 
would  finally  cause  the  chilled  part  to  separate  from  the  gray- 
iron  center  on  account  of  the  mottling  and  legging  not  being 
sufficient  to  properly  hold  the  two  parts  together.  The  gray 
iron  would  finally  crumble  out  and  leave  a  hole  in  the  wheel. 

When  in  use  the  application  of  the  brake  to  the  wheel 
causes  the  generation  of  heat.  To  determine  the  ability  of 
the  wheel  to  stand  up  under  the  application  of  the  brake,  the 
following  test  is  made :  From  a  number  of  wheels  one  is  selected 
and  placed  on  a  green-sand  bed  with  the  flange  of  the  wheel 
down.  A  dam  of  molding  sand  is  built  around  it,  leaving  a 
space  of  about  one  and  one-eighth  inches  between  the  dam  and 
wheel.  Into  this  space  molten  iron  is  poured,  being  taken  from 
the  cupola  under  the  specifications  of  the  Master  Car  Builders' 
Association,  and  poured  into  the  channelway  in  two  places. 
The  wheel  is  left  for  a  specified  time,  after  which  it  is  removed 
and  examined,  and  from  the  action  of  this  test  wheel  under 
treatment,  the  lot  of  wheels  may  be  accepted  or  rejected.  This 
test  is  known  as  the  thermal  test. 

A  second  test,  to  determine  the  strength  of  the  wheel,  is 
made  by  dropping  a  two-hundred-pound  weight  a  distance  of 
nine  feet  on  the  center  of  a  625-pound  wheel,  the  wheel 
being  placed  flange  down  on  an  anvil  supporting  only  the  rim. 
The  wheel  must  sustain  ten  such  blows  to  be  accepted.  A 
675-pound  wheel  must  sustain  twelve  blows,  with  a  drop  to 
the  weight  of  ten  feet,  while  a  725-pound  wheel  must  sus- 
tain twelve  blows  from  a  height  of  twelve  feet. 

Formerly  car- wheel  foundries  were  equipped  with  jib  cranes 
around  which  the  wheels  were  molded  and  poured.  The  iron 
was  brought  to  the  floors  in  wheel  ladles  which  were  hoisted 
by  a  crane  for  pouring  into  the  molds.  With  this  arrangement 
of  circular  floors  much  space  was  necessarily  unoccupied. 
The  more  modern  wheel  foundries  have  adopted  what  is  known 
as  the  straight-line  system  which  reduces  the  unoccupied  space 
to  a  minimum.  Typical  straight-line  plants  are  those  of  the 
Chicago,  Milwaukee  and  St.  Paul  Railroad  at  Milwaukee,  Wis., 
and  that  of  the  Dixon  Car  Wheel  Foundry,  Houston,  Texas. 


MOLDING  CAR-WHEELS  89 

At  the  Milwaukee  plant,  the  wheel  flasks  are  arranged  in 
straight  lines  across  the  foundry,  resting  on.  two  rails,  spaced 
twelve  feet  centers.  The  cupolas  deliver  to  large  reservoir 
ladles  which  are  electrically  tipped.  In  front  of  the  reservoir 
ladles  is  a  track  extending  the  length  of  the  foundry,  on  which 
two  ladle  trains  are  electrically  operated  from  in  front  of  the 
ladles  to  opposite  ends  of  the  foundry.  The  movement  of  the 
ladle  trains  and  the  tipping  of  the  reservoir  ladle  is  controlled 
from  a  pulpit  at  the  cupola.  Each  car  in  the  ladle  train  carries 
two  ladles,  which  can  be  lifted  from  the  car  at  the  various 
pouring  floors  by  means  of  overhead  trolley  hoists  over  each 
floor.  The  molds  are  poured  from  the  ladles  suspended  from 
the  trolleys. 

After  pouring  six  wheels,  the  men  begin  to  shake  them  out 
of  the  molds  and  to  deliver  them  by  means  of  the  overhead 
trolleys  to  the  hot-wheel  cars  on  the  hot-wheel  tracks  extend- 
ing the  length  of  the  foundry  to  the  annealing  pits  where  the 
pouring  heads  are  broken  from  the  wheels  and  the  center 
cores  knocked  out. 

In  addition  to  car-wheels,  many  different  styles  of  castings 
are  produced  in  molds  made  partly  of  molding  sand  and  partly 
of  iron.  Certain  cotton-machinery  castings  are  made  in  iron 
molds  in  order  that  the  wearing  surfaces  will  be  chilled  and 
thus  have  a  harder  skin  as  the  chilling  of  the  hot  iron  hardens 
it,  due  to  the  quick  cooling.  The  common  gray-iron  casting, 
however,  is  not  hardened  to  any  great  depth  by  pouring  it 
against  an  iron  surface,  if  the  casting  is  of  any  great  thickness. 
In  order  to  obtain  a  chilled  surface  of  any  depth  it  is  necessary 
to  have  an  iron  of  such  chemical  analysis  as  will  be  affected 
by  the  chill  forming  a  portion  of  the  mold.  See  Chapter  XXIII 
for  analyses  of  irons  for  use  in  chilled  castings. 


CHAPTER  IX 

SKIN-DRIED  MOLDS 

THE  skin-dried  mold  is  made  of  green  sand  with  a  facing 
composed  of  varying  mixtures  of  sand  and  flour  and  after 
completion  the  surface  is  dried  by  heat  to  a  depth  ranging  from 
one-half  inch  to  several  inches.  Thus  the  skin-dried  mold 
occupies  a  place  midway  between  the  green-sand  mold  and 
the  dry-sand  mold.  The  class  of  castings  which  are  poured  in 
skin-dried  molds,  will  include  locomotive  cylinders  and  station- 
ary engine  frames  and  cylinders.  Later  in  this  chapter  we 
will  consider  the  making  of  a  skin-dried  mold  for  a  Tangye 
engine  frame. 

The  molds  are  dried  in  several  different  manners.  The 
smaller  molds  may  be  placed  in  an  oven  and  baked  until  the 
surface  has  been  dried  to  the  required  depth.  In  the  natural- 
gas  belt,  heat  is  applied  to  the  mold  by  means  of  a  portable 
gas  torch,  and,  the  gas  being  under  pressure,  the  flame  may  be 
directed  against  any  portion  or  into  a  deep  pocket  of  the  mold 
as  desired.  Where  gas  is  not  available,  the  oil  torch  is  fre- 
quently used  for  this  purpose,  providing  compressed  air  is  sup- 
plied to  the  foundry.  The  oil  torch  has  the  special  advantage  of 
regulation  of  the  flame;  thus  an  intensely  hot  blue  flame  may  be 
used  or  a  moderately  hot  large  yellow  flame,  or  any  flame  be- 
tween these  two  extremes.  Either  crude  or  kerosene  oil  may  be 
used,  depending  on  the  air  pressure  available.  Sixty-five  pounds 
per  square  inch  is  required  for  this  work  with  crude  oil  while 
but  twenty  pounds  is  necessary  with  kerosene.  In  using  the 
oil  torch,  some  experience  is  necessary  to  obtain  the  best 
results.  Too  sharp  and  too  quick  a  heat  applied  to  the  face  of 
the  mold,  may  cause  the  sand  to  blister  and  fall.  Heat  should 
be  applied  gradually  and  its  intensity  slowly  increased  as  the 
mold  dries  out.  After  a  time,  a  heat  of  considerable  intensity 
90 


SKIN-DRIED   MOLDS  QI 

may  be  applied  without  danger  of  burning  the  face  of  the 
mold. 

Where  neither  natural  gas  nor  the  oil  torch  is  available,  fire 
baskets  may  be  used  for  drying  the  mold.  These  are  baskets 
made  of  iron  in  which  is  built  a  fire  of  charcoal  or  gas  coke.  The 
fire  is  built  in  them  outside  the  mold  and,  when  it  is  well  alight, 
the  basket  is  lowered  a  little  at  a  time  until  it  is  at  the  proper 
distance  from  the  bottom  of  the  mold.  If  lowered  too  close  to 
the  face  of  the  mold  immediately,  the  mold  will  be  damaged 
and  a  great  deal  of  patching  necessitated.  When  the  mold  is 
partly  dried,  the  process  can  be  hurried  by  building  a  moderate 
fire,  and  covering  the  mold. 

The  sand  mixtures  used  to  form  the  face  of  the  mold  vary 
with  the  locality.  Either  fire  sand  or  ground  silica  rock  is 
added  to  the  facing  mixture,  depending  on  the  kind  of  work. 
If  neither  is  available,  the  facing  mixtures  should  contain 
lake  or  hill  sand.  The  addition  of  a  highly  refractory  and 
coarser  sand,  to  the  ordinary  molding  sand,  not  only  produces 
a  more  porous-faced  mold  through  which  steam  will  escape 
while  the  face  of  the  mold  is  being  dried,  but  it  also  assists  the 
molding  sand  in  resisting  the  action  of  metal.  The  body  of  a 
skin-dried  mold  should  be  well  vented  to  carry  off  the  steam 
and  gases  generated  in  drying.  Large  green-sand  hanging  cores 
are  often  skin-dried  and  scabbing  thereby  avoided. 

MOLDING  AN  ENGINE  BED  IN  A  SKIN-DRIED  MOLD 

Fig.  56  shows  an  engine  frame  of  the  Tangye  type  which 
can  be  cast  to  advantage  in  a  skin-dried  mold.  As  there  will 
be  considerable  side  strain  in  pouring  a  casting  of  this  character, 
necessitating  a  heavy  flask  and  considerable  special  rigging,  the 
mold  will  be  made  in  a  pit.  The  pit  is  prepared  as  described  in 
Chapter  V,  and,  when  ready,  the  pattern  is  leveled  in  position 
by  means  of  wedges  and  sand  is  rammed  to  within  a  few  inches 
of  the  backbone  A  of  the  pattern,  Fig.  57.  Facing  sand  is 
then  tucked  and  rammed  below  and  around  the  sides  of  the 
backbone  and  continued  under  the  remainder  of  the  bed. 


92  FOUNDRY   PRACTICE 

When  enough  is  in  place  to  hold  the  pattern  in  position,  the 
pattern  is  lifted  from  the  pit  and  the  surfaces  already  finished 
are  well  vented  down  to  the  cinder  bed,  the  sides  and  edges 
of  the  backbone  are  nailed,  and  the  face  is  finished.  The 
pattern  is  then  replaced  and  is  faced  and  rammed  up  with 
black  sand  to  a  point  where  the  iron  plate  supporting  the  main 
core  can  be  placed  under  the  core-print.  This  plate  should 
extend  some  distance  on  either  side  of  the  core-print  into  the 
sand  as  shown  in  the  detail  Fig.  58.  After  these  plates  are 
placed,  facing  and  ramming  are  continued  until  the  saijd  is 
high  enough  to  permit  placing  the  gate  cores  B,  Fig.  57, 
between  the  jaws  C  C  of  the  pattern.  These  are  bedded  in  the 
sand  and  a  cinder  bed  D  placed  over  them,  a  vent  pipe  being 
inserted  in  the  cinder  bed  for  the  escape  of  gas.  Pouring  gate 
cores  F  and  upright  gate-sticks  G  are  placed  at  the  end  of  the 
pattern.  Iron  rings  are  set  around  these  to  re-enforce  them  to 
resist  the  strain  generated  in  the  sand  while  pouring.  When 
the  sand  has  reached  the  round  portion  of  the  pattern,  it  is 
vented  below  the  pattern  and  the  vents  are  covered  with 
cinders  which,  in  turn,  are  covered  with  paper.  The  pattern 
is  faced  and  sand  rammed  in  until  it  has  reached  the  floor  line. 
Referring  now  to  the  detail  Fig.  58,  the  method  of  inserting  rods 
to  strengthen  the  face  of  the  mold  is  shown.  These  rods  should 
extend  to  within  about  two  inches  of  the  face  of  the  mold,  there 
being  four  layers  of  rods  set  in  a  pattern  of  this  depth.  A 
cinder  bed  extending  beyond  the  end  of  the  cope  is  built  along- 
side each  edge  of  the  pattern  at  C,  Fig.  58,  a  short  distance 
below  the  floor  line.  From  this  cinder  bed  vents  are  made 
with  a  large  vent-wire  down  to  the  lower  cinder  bed  as  shown. 
In  placing  these  cinder  beds,  they  are  well  rammed  with  the 
butt  of  the  rammer  in  order  to  assist  in  resisting  the  side  strain 
when  the  mold  is  poured. 

The  inside  of  the  pattern  is  a  succession  of  deep  pockets  of 
sand  to  form  the  cope  side  and,  in  order  to  lift  out  these  pockets 
of  sand  from  the  pattern,  skeletons  or  grids  are  made  to  con- 
form to  the  face  of  the  pattern  as  shown  in  Fig.  57.  These  grids 
are  secured  to  the  cope  by  bolts  /.  The  cope  is  lowered  into 


MOLDING  AN   ENGINE   BED 


93 


94 


FOUNDRY   PRACTICE 


place,  being  made  wide  enough  to  rest  on  upright  timbers 
which  extend  up  from  the  binders  in  the  pit  bottom.  It  is 
guided  by  stakes  driven  into  the  sand  and  the  bolts  /  for  hold- 
ing the  grids  are  then  placed.  The  cope  is  next  removed  to- 
gether with  the  skeleton,  and  parting  sand  is  dusted  on  the 
joint  and  facing  sand  is  placed  inside  the  pattern  to  a  depth 
five-eighths  inch.  The  skeletons  are  then  lowered  into  place 


FIG.  58. — MOLD  OF  END  OF  PATTERN. 

and  rapped  down.  Gaggers  are  set  in  the  skeletons  exactly 
as  though  these  were  the  barred  cope  flask,  and  on  top  of  each 
skeleton  pieces  of  joist  are  set  to  come  up  level  to  the  top  of 
the  pattern. 

A  water  pocket  is  to  be  formed  in  the  casting  underneath 
the  jaws  C  C  by  means  of  the  core  K.  On  this  core  are  four 
prints  over  each  of  which  the  gas  pipe  /  is  set  extending  to 
the  top  of  the  cope.  These  gas  pipes  are  rammed  up  in  the 
cope  with  the  sand.  The  inside  of  the  pattern  is  faced  and 
backed  with  black  sand  which  is  rammed  to  the  point  where 
the  green-sand  core  extends  under  the  ribs  A,  Fig.  59,  also 
shown  at  L,  Fig.  57.  This  rib  extends  into  the  inside  of  the 
cope  and  causes  an  overhanging  core  to  extend  all  around  the 
pattern.  The  inside  of  this  flange  being  faced,  five-eighths  inch 
rods  are  laid  from  the  body  of  the  hanging  sand  on  the  cope 
side  to  the  sand  under  the  flange,  to  support  it.  This  sand  is 


MOLDING   AN   ENGINE   BED  95 

vented,  the  vents  being  brought  out  four  inches  away  from 
the  pattern  and  the  vents  covered  with  cinders,  as  shown  at 
M.  We  now  have  a  body  of  sand  covering  the  skeletons  and 
forming  the  inside  of  the  pattern.  A  long  channel  is  scooped 
out  in  the  center  of  each  pocket  and  these  are  vented  to  this 
channel  which  is  then  covered  with  cinders  and  filled  with 
sand  up  to  the  floor  level.  The  joint  is  made,  parting  sand 
dusted  on,  and  the  cope  flask  replaced.  The  bolts  /  are  at- 
tached to  the  flask,  the  pipes  /  and  the  gate-sticks  set  to  the 
cinder  beds,  and  the  joists  in  the  pockets  are  wedged  down  to 
hold  the  skeletons  firmly  in  position.  The  cope  is  gaggered 
and  rammed  with  successive  rammings  of  sand  in  the  usual 
fashion.  The  cope  is  hoisted  off  with  the  pockets  of  sand, 
forming  the  inside  pattern,  suspended  from  it.  It  is  lowered 
on  to  trestles  and  the  sides  propped  up  with  pieces  of  joist 
to  insure  it  against  springing  on  account  of  the  weight  of  sand 
suspended  from  it.  The  flanges  A,  Fig.  59,  are  made  loose  and 
are  drawn  out  of  the  mold  with  the  cope.  They  are  now  re- 
moved from  the  sand  and  the  cope  is  finished,  after  which  it  is 
skin-dried  to  a  depth  of  an  inch  and  a  half.  When  finishing 
the  cope,  the  edges  of  the  pockets  are  nailed  wherever  there  is 
any  liability  of  the  cope  cutting  on  account  of  the  flow  of  iron. 
A  gas  or  oil  flame  is  used  for  drying,  care  being  taken  to  direct 
the  flame  into  the  pockets  in  the  cope  formed  by  the  various 
ribs. 

The  pattern  in  the  floor  is  next  boshed,  rapped,  and  drawn 
from  the  sand.  The  pieces  D,  Fig.  58,  are  loose  and  are  re- 
moved from  the  sand  after  the  main  portion  of  the  pattern  is 
drawn.  The  various  edges,  where  there  is  a  liability  to  wash- 
ing, are  nailed  as  is  also  the  face  of  the  mold  near  the  gate. 
The  mold  is  then  sprayed  with  molasses  water  and  skin-dried 
with  fire  baskets,  as  described  earlier  in  the  chapter. 

The  main  core  is  made  in  two  halves,  the  core-print  being 
formed  by  a  loose  piece  in  the  core  box.  The  two  halves  of 
the  core  are  bolted  together  with  the  bolts  R,  but  before  this 
is  done,  the  core  S,  which  is  made  in  a  special  core  box,  is 
bolted  to  the  upper  half  of  the  main  core  by  the  bolt  T.  The 


96  FOUNDRY   PRACTICE 

vent  from  this  core  is  led  to  the  vent  of  the  main  core.  Each 
half  of  the  main  core  is  made  on  a  solid  cast-iron  core  arbor 
which  takes  the  strain  due  to  the  heavy  weight  of  the  core. 
The  bottom  of  the  core  is  rodded  as  shown  at  U  to  hold  it  to 
the  arbors.  This  is  not  required  with  the  upper  half  which 
is  not  suspended.  The  cores  forming  the  openings  in  the  side 
of  the  bed  E  and  C,  Fig.  56,  are  first  placed,  after  which  the 
main  core  is  set.  A  special  stop-off  piece  B,  Fig.  59,  is  used  to 
form  the  side  of  the  mold  at  that  point  and,  after  it  is  placed, 
a  bed  of  cinders  W,  Fig.  57,  is  made  and  vented  with  the  pipe 
X.  A  spud  or  piece  of  timber  is  set  on  either  end  of  the  core 
arbor,  being  cut  off  level  with  the  floor.  Sand  is  now  stopped 
in  over  the  end  of  the  core  at  B,  the  regular  facing  mixture 
being  used  against  the  stop-off  piece,  backed  up  with  black 
sand  rammed  firmly  against  it.  The  stop-off  core  Y  at  the 
opposite  end  of  the  mold  is  placed  as  shown,  cinders  and  the 
vent  pipe  for  venting  the  core  are  laid  in,  and  black  sand  ram- 
med in  back  of  it.  After  the  core  Y  is  set,  the  joint  between 
it  and  the  sides  of  the  mold  is  filled  in  and  dried.  The  core  K, 
forming  the  water  box  between  the  jaws  of  the  pattern,  is  now 
placed  in  the  cope.  This  core  is  made  with  a  staple  in  each 
round  core-print,  over  which, it  will  be  recollected,  the  gas  pipes 
/  were  set,  and  rammed  into  the  cope.  Wires  are  inserted 
through  these  staples  and  threaded  through  the  gas  pipes  and 
drawn  tight  to  bring  the  core  against  the  chaplets  A  B.  The 
wires  are  then  fastened  to  a  rod  at  the  upper  end  of  the  gas  pipe 
and  this  rod  is  wedged  up  to  hold  the  core  in  position  against 
the  chaplets.  The  pipes  J  also  act  as  vents  to  the  core.  The 
edges  of  the  pipe  are  covered  with  paste  and  a  small  amount 
is  placed  inside  the  pipes  to  prevent  iron  entering.  Vent-wires 
are  inserted  in  the  pipe,  after  which  they  are  filled  with  sand 
and  the  vent-wire  withdrawn. 

The  bolt  cores  D,  Fig.  56,  are  set  in  the  prints  and  the  shelf 
core,  Fig.  59,  C,  is  placed,  after  which  the  cope  is  tried  on.  In 
Fig.  56  prints  are  shown  for  the  bolt  cores  on  the  cope  side  of 
the  pattern.  The  author  considers  this  poor  practice  and 
recommends  having  the  cope  side  flush,  so  that  the  cope  will 


MOLDING    AN    ENGINE    BED 


97 


98  FOUNDRY    PRACTICE 

bear  on  the  top  of  the  cores  which  should  be  steadied  with 
nails  set  alongside  the  cores.  This  will  avoid  pulling  'down 
part  of  the  cope  when  lifting  it  after  trying  on  the  pattern. 
The  name-plate  core  is  next  set,  after  which  the  cope  is  once 
more  tried  on,  and,  every  thing  being  satisfactory,  the  joint  is 
pasted  wherever  the  casting  comes  near  the  side  of  the  cope, 
and  the  mold  finally  closed. 

It  will  be  observed  that  the  pouring  gates  are  outside  the 
cope,  as  this  makes  a  shorter  cope  and  one  easier  to  handle. 
The  upright  gates,  it  will  be  remembered,  were  ringed  and 
rammed  up  with  facing  sand  which  is  vented  to  permit  the 
escape  of  gas  from  the  gates. 

Binders  are  now  placed  across  the  top  of  the  cope  and  it 
is  fastened  firmly  to  the  floor  by  means  of  the  hook  bolts  shown 
connecting  with  the  eye-bolts  with  the  binders  in  the  pit.  One 
binder  is  placed  across  the  spud  G  H  in  the  cope,  which  is 
wedged  down  to  hold  the  end  of  the  main  core  in  position. 
The  spud  at  the  opposite  end  is  wedged  down  below  the  end 
of  the  flask.  The  facing  sand  is  next  scraped  away  from  the 
upright  pouring  gates,  where  dry,  and  replaced  with  fresh 
sand.  Runner  boxes  are  placed  in  position  and  runners  built 
to  pour  the  casting  from  each  end,  cores  being  placed  in  the 
bottom  of  each  runner  box  for  the  iron  to  fall  on  as  it  is  poured. 
Heavy  risers  were  placed  on  either  side  of  the  pattern  in 'the 
cope  for  feeder  heads  and  these  are  built  out  above  the  cope 
in  order  to  give  a  greater  head.  Pieces  of  oiled  paper  are 
placed  in  the  vent  pipe  to  be  lighted  when  pouring  for  purpose 
of  igniting  the  escaping  gases.  Holes  are  dug  at  the  ends  of 
the  mold,  back  of  the  runners,  to  permit  the  lip  of  the  ladle 
in  pouring  to  be  as  close  as  possible  to  the  runner.  In  pour- 
ing, the  ladle  at  the  left  which  feeds  the  deepest  part  of  the 
casting,  is  first  started  and  afterward  the  ladle  at  the  right. 

The  mold  is  filled  so  that  the  iron  flows  up  in  the  risers  to 
nearly  the  top  of  the  cope,  and  pouring  is  stopped  when  the 
iron  shows  a  tendency  to  rise  above  this  point  in  the  riser. 
They  are  kept  covered  until  the  escaping  gas  indicates  that 
the  mold  is  nearly  filled,  and  the  iron  remaining  in  the  run- 


MOLDING  AN   ENGINE    BED  99 

ners  is  then  depended  on  to  completely  fill  the  mold.  To 
provide  against  the  emergency  of  iron  overflowing  the  top  of 
the  cope  and  finding  its  way  into  the  vents,  flow-offs  are  pro- 
vided. The  casting  should  be  churned  for  some  considerable 
time  and  the  iron  fed  to  the  risers  during  the  operation  must 
be  extremely  hot.  The  direction  of  flow  of  the  molten  iron 
filling  the  mold  is  shown  by  arrows  in  the  gates. 

Shortly  after  the  mold  is  filled,  the  iron  will  become  set 
in  the  pouring  gates  and  the  runners  may  then  be  broken 
away  and  broken  up  while  hot.  When  the  casting  has  cooled 
somewhat,  the  binders  are  removed  as  is  also  the  rod  holding 
the  water  core  in  place.  The  nuts  holding  the  skeletons  are 
removed,  the  cope  is  hoisted,  and  the  sand  knocked  out  and 
allowed  to  fall  on  top  of  the  casting,  which  will  require  about 
two  days  to  cool  off  sufficiently  to  permit  its  being  lifted  from 
the  sand. 


CHAPTER  X 

DRY-SAND  MOLDS 

DRY-SAND  molds  are  used  for  intricate  castings  in  which 
the  walls  must  be  of  a  positive  thickness  or  in  which  large 
bodies  of  metal  must  remain  fluid  for  a  considerable  period  of 
time.  Dry-sand  molds  are  molds  made  of  a  special  mixture  of 
rather  coarse  sand  which  are  afterward  dried  or  baked  in  an 
oven.  Molds  treated  in  this  fashion  possess  great  rigidity  and 
will  stand  rather  severe  usage.  After  being  baked,  they  may 
be  poured  in  any  position  without  damage  to  the  mold.  Dry- 
sand  molds  are  principally  used  for  steam-  and  gas-engine 
cylinders,  pump,  air  compressor  and  hydraulic  cylinders, 
printing-press  cylinders  and  rolls,  rolling  mill  rolls,  anvil 
blocks,  engine  beds,  and  similar  heavy  castings.  The  following 
mixtures  are  given  by  West1  as  suitable  sands  for  the  different 
classes  of  castings: — 

Large  spur  gears:  12  pails  of  lake  sand,  12  pails  strong 
loam  sand,  4  pails  molding  sand,  I  to  10  pails  of  coke  dust,  ij^ 
pails  of  flour;  wet  with  water. 

Large  bevel  wheels:  one  part  molding  sand,  one  part  Jersey 
sand,  one  part  seacoal  to  16  parts  of  sand  mixture;  wet  with 
thin  claywash. 

Engine  cylinders:  6  pails  molding  sand,  i>£  pails  of  lake 
or  bank  sand,  30  parts  sand  mixture  to  one  part  of  flour;  wet 
with  claywash. 

Another  mixture  for  cylinders  is  4  parts  of  fair  loam,  one 
part  of  lake  sand,  one  part  coke  dust  or  seacoal  to  14  parts 
sand  mixture;  wet  with  claywash  according  to  the  clayeyness 
of  the  loam.  The  backing  used  with  this  facing  is  5  parts  loam 
and  I  part  lake  sand ;  wet  with  claywash.  A  good  mixture  for 
ordinary  work  is:  i  part  molding  sand,  I  part  bank  sand;  wet 

l"  American  Foundry  Practice,"  p.  353. 


DRY-SAND  MOLDS  IOI 

with  claywash  and  use  I  part  of  flour  to  30  parts  of  mixture 
or  I  part  blacking  to  20  parts  of  mixture. 

A  mixture  with  a  clay  loam  for  cylinder  castings  is  as 
follows:  6  parts  strong  loam  sand,  6  parts  lake  sand,  2  parts 
old  dry  sand,  flour  I  to  40,  seacoal  I  to  14;  wet  with  water. 
A  mixture  used  for  rolling  mill  rolls:  2  parts  old  dry  sand,  I 
part  baked  sand,  seacoal  I  to  12,  flour  I  to  18;  make  as  wet  as 
can  be  worked  with  claywash. 

The  author  has  had  good  results  with  a  dry  sand  composed 
of  equal  parts  of  coarse  molding  sand  and  coarse  New  Jersey 
fire  sand.  Flour  or  rye  meal  is  added  to  this  mixture  in  the 
proportion  of  I  part  flour  to  14  parts  mixture.  The  mass  is 
mixed  thoroughly  and  then  dampened  with  molasses  water 
made  of  I  part  molasses  and  16  parts  water.  If  fire  sand  is  not 
available,  ground  silica  rock  may  be  substituted. 

In  molding,  the  pattern  is  faced  with  one  of  the  above 
mixtures  and  the  facing  is  backed  up  with  what  has  become  a 
burnt  mixture  of  the  facing  wet  with  clay  water,  or  with  com- 
mon black  sand.  The  mold  itself  is  usually  made  in  the  same 
manner  as  a  green-sand  mold.  The  flask,  however,  especially 
for  large  castings,  is  somewhat  different,  being  made  of  iron 
with  slotted  holes  in  the  side  as  shown  in  Fig.  64.  These  holes 
are  for  the  purpose  of  venting  the  mold,  five-sixteenths  inch 
vent  rods  being  inserted  through  them,  extending  into  the 
mold  to  within  a  short  distance  of  the  pattern. 

A  typical  dry-sand  job  is  the  molding  of  a  Corliss  engine 
cylinder,  the  various  operations  being  shown  in  Figs.  60-69. 
When  pouring  such  cylinders,  they  are  usually  poured  with 
the  steam  ports  vertical  in  order  to  give  cleaner  and  sounder 
valve  seats  than  would  be  obtained  were  the  molds  poured  in 
any  other  position.  In  molding,  the  pattern  A,  Fig.  62,  is 
placed  on  the  mold-board  with  the  drag  around  it,  joint  side 
down.  Gate-sticks  B  forming  upright  pouring  gates  are  set 
and  held  the  proper  distance  away  from  the  cylinder  pattern 
by  the  sprue  C.  The  pattern  is  faced  with  the  dry-sand 
mixture,  which  is  backed  up  with  old  sand,  wet  with  clay 
water.  The  gate-sticks  are  faced  and  the  outside  of  the  pattern 


102  FOUNDRY    PRACTICE 

faced  and  rammed  up  with  successive  rammings  of  sand,  vent 
rods  being  introduced  through  the  slotted  holes  as  the  flask 
is  filled,  and  afterward  withdrawn,  leaving  vents  throughout 
the  mold. 

When  the  top  of  the  steam  and  exhaust  chests  on  the 
pattern  are  reached,  deep  pockets  will  be  formed  by  the  exten- 
sions of  the  chest  above  the  round  of  the  barrel.  In  these  are 
placed  rods  D,  Fig.  63,  which  have  been  claywashed,  to 
support  these  pockets.  The  sand  is  vented  around  the  rods. 
A  similar  procedure  is  followed  when  the  wrist-plate  seat  E 
is  encountered.  On  reaching  the  main  core-print,  an  iron 
plate  is  laid  on  the  print  and  rammed  in  the  mold  to  support 
the  heavy  center  core.  Facing  sand  is  covered  over  the  pattern 
and  heap  sand  rammed  in,  in  successive  rammings,  until  the 
flask  is  filled.  The  remaining  operations  are  carried  out  as 
they  would  be  for  any  green-sand  mold. 

After  the  joint  is  made  and  the  cope  placed  in  position, 
with  the  gate-sticks  and  gaggers  set,  the  cope  is  rammed  up 
with  vent  rods  in  the  side.  On  top  of  each  port  post,  a  large 
plug  of  the  same  size  as  the  top  of  the  core-print  is  placed  and 
rammed  up  and,  on  each  end  flange  of  the  cylinder,  a  riser  is 
placed  to  serve  as  a  flow-off.  Screws  for  securing  the  cope 
half  of  the  pattern  in  the  flask  are  inserted,  the  cope  is  faced, 
and  heap  sand  shoveled  in  to  fill  the  flask  and  rammed  up. 
Bars  are  shoved  through  the  eyes  of  the  screw-eyes  screwed 
into  the  pattern  and  wedged  in  place  and  the  cope  is  lifted 
off.  The  screw-eyes  are  removed  and  the  holes  left  by  them 
are  stopped  up,  after  which  the  joint  is  made  and  the  pattern 
is  boshed  with  molasses  water,  it  then  being  rapped  and  drawn. 
Usually,  in  making  the  joint,  the  corners  are  nailed  and 
sometimes  the  entire  joint  around  the  edge  of  the  pattern  is 
nailed,  since  there  are  but  few  bars  used  in  the  cope  of  a  dry- 
sand  mold. 

In  finishing  a  dry-sand  mold,  breaks  at  the  corners  should 
be  repaired  by  first  placing  nails  to  secure  the  sand,  after  which 
the  broken  sand  should  be  replaced  with  the  fingers,  and 
shaved  to  the  shape  of  the  mold  as  closely  as  possible.  Should 


DRY-SAND   MOLDS  1 03 

wet  mud  be  laid  on  these  breaks  with  a  trowel,  it  will  scab  off 
when  the  mold  is  poured  and  injure  the  casting.  After  the 
mold  is  finished  and  before  it  is  baked,  blacking  is  applied. 
The  blacking  is  mixed  to  about  the  consistency  of  cream  and 
applied  evenly  over  the  entire  surface  of  the  mold  with  the 
swab.  After  it  has  set  for  a  few  moments,  it  is  slicked  with  the 
trowel  which  is  held  at  a  slight  angle  to  the  surface.  If  the 
trowel  is  allowed  to  lie  flat  against  the  surface  when  the  black- 
ing is  slicked,  a  part  of  the  face  of  the  mold  will  follow  the 
trowel  when  it  is  lifted.  Larger  molds  are  best  blacked  green, 
that  is  before  baking,  while  the  smaller  sizes  are  more  satis- 
factory if  blacked  after  drying.  After  blacking  a  green  mold, 
it  should  be  brushed  over  with  molasses  water  to  smooth  the 
blacking  and  give  a  smooth  surface  to  the  casting.  The  gate 
is  cut  and  the  mold  placed  in  a  proper  oven  for  baking,  the 
oven  used  being  one  adapted  for  core  work. 

Referring  to  Figs.  68  and  69,  the  method  of  making  the 
cores  for  the  exhaust  chambers  is  shown.  In  making  this 
core,  the  iron  plate  A  is  placed  on  trestles  and  over  this  four 
smaller  plates  B  are  set,  with  dryers  at  each  end.  The  skeleton 
or  grid  D  is  laid  on  these  plates  with  the  part  which  is  to  go  in 
the  dryer  in  place.  The  skeleton  core  box  E  is  placed  in  posi- 
tion and  core  sand  tucked  under  the  skeleton  and  rammed 
around  it.  Iron  rods,  of  at  least  one-quarter  inch  diameter, 
are  inserted  through  holes  in  the  end  of  the  core  box  and  rest 
on  the  vent  rods  lying  in  the  post  part  of  the  core  box  at  F. 
The  core  box  is  then  rammed  full  and  swept  off  on  top  with 
the  sweep  G.  The  core  is  hollowed  to  form  the  proper  thick- 
ness of  the  cylinder  barrel  by  means  of  the  round  surface  H 
on  the  sweep.  The  ports  /  are  next  rammed  up.  Pieces  of 
wire  of  the  proper  length,  inserted  in  the  post  part  of  the  core 
box,  support  the  sand  forming  the  core  for  the  port  at  /.  The 
mixture  used  in  making  this  portion  of  the  core  usually  has 
seacoal  added  in  order  to  leave  a  clean  port  in  the  casting. 
Nails  are  placed  along  the  top  edge  of  the  core  and  it  is  vented 
in  the  same  manner  as  a  mold.  The  top  is  slicked  lightly  and 
the  vent  rods  withdrawn.  The  screws  /  are  removed  and  the 


104 


FOUNDRY   PRACTICE 


portion  K  lifted  off,  leaving  exposed  the  end  of  the  core.  The 
holes  left  by  the  vent  rods  are  then  filled  with  paste  to  prevent 
iron  working  into  them  later.  The  screws  L  are  withdrawn 


FlQ.69.  TOP  OF  EXHAUST  CORE  BOX. 

L 


Eia.62.    END  OF  PATTERN  IN  MW_  FlO.68.   SIDE  VIEW  OF  PATTERN  IN  DRAG     „ 


FlG.ae.   RUNNER  AND  FLOWOFF  BUILT,  SIDE  VIEW. 


FIG.67.    READY  FOR  POURING. 


FIGS.  60-69. — MOLDING  A  CORLISS  ENGINE  CYLINDER  IN  DRY  SAND. 

and  the  sides  M  removed  as  is  also  the  stop  piece  N.  The 
object  of  this  piece  is  to  determine  the  proper  length  of  the 
core  and  it  can  be  set  at  any  desired  point  in  the  core 


DRY- SAND   MOLDS  1 05 

box.  There  now  only  remains  portion  O  of  the  core  box 
to  be  removed  and  the  core  remains  in  the  dryer  C  and  on 
the  plates  B.  The  core  is  then  finished  all  over  and,  if 
of  large  size,  is  blackened  before  being  dried.  The  steam- 
chest  core  is  made  in  one  piece  with  the  post  and  port  at 
each  end. 

The  mold,  when  baked,  is  placed  in  position  for  pouring. 
The  drag  is  examined  and,  if  properly  dried,  is  cleaned  out  and 
the  steam-chest  core  tried  in.  The  vent  hole  in  the  bottom  of 
the  post  is  stopped  to  prevent  iron  working  under  the  core  and 
rising  in  the  vents.  This  vent  should  be  left  open  until  the 
core  is  ready  for  use,  as  it  is  then  possible  to  make  sure  that 
all  vents  are  open.  The  exhaust-chest  core  is  set  after  the 
steam-chest  core.  This  core  is  in  two  pieces  and  a  partition 
is  formed  in  the  middle  of  the  exhaust  chest.  Consequently 
each  core  has  but  a  single  post  at  one  end  to  support  it  and  it 
must  be  supported  at  the  opposite  end  by  chaplets.  The  barrel 
center  or  main  core  is  now  placed  by  means  of  the  crane  and 
is  set  in  between  the  port  cores  as  shown  in  Fig.  65. 

When  the  ports  of  the  exhaust-chest  core  were  made,  staples 
were  set  in  the  back  of  the  core  where  the  center  of  the  nozzle 
cores  were  to  come.  Wires  are  twisted  and  passed  through 
the  staples  and  holes  in  the  center  of  the  nozzle  cores  T,  Fig.  65, 
and  the  exhaust-chest  core  is  drawn  tightly  against  the  nozzle 
core  by  passing  the  wire  through  the  side  of  the  flask  at  U, 
Fig.  64,  and  twisting  it  around  a  rod  which  is  then  wedged  out 
from  the  side  of  the  flask.  A  vent  is  arranged  to  bring  the 
gas  from  the  nozzle  cores,  this  being  cut  usually  while  the  mold 
is  green.  Flour  is  next  placed  on  the  joint  of  the  mold  and 
chaplets  set  on  the  exhaust-chest  cores,  after  which  the  cope  is 
tried  on. 

It  will  be  recollected  that  when  the  cope  was  rammed,  a 
large  plug  was  rammed  up  on  top  of  each  post  core-print. 
When  the  cope  is  hoisted,  a  man  looks  through  each  of  these 
holes  and  guides  the  tops  of  the  posts  of  the  chest  cores  into 
their  proper  print.  This  operation  requires  four  men,  while 
two  more  are  necessary  to  guide  the  flask  itself  until  it  reaches 


106  FOUNDRY    PRACTICE 

the  long  guide  pins  on  the  flask.  When  the  cope  is  lowered  to  a 
bearing  it  is  clamped  with  a  few  clamps  which  are  immediately 
removed  and  the  cope  once  more  lifted  off,  after  which  the 
mold  and  cores  are  examined  to  see  that  no  portion  is  crushed 
by  reason  of  the  cope  bearing  too  hard  on  the  drag.  It  being 
determined  that  the  mold  bears  satisfactorily,  as  shown  by 
the  flour  on  the  joint,  a  line  of  thick  paste  is  laid  along  the 
joint  adjoining  the  edge  of  the  flask  and  over  the  ends  of  the 
nozzle  cores  to  prevent  iron  flowing  into  the  vents.  After  the 
mold  has  been  finally  closed,  the  pouring  basin  is  built  and 
flow-off  channels  arranged  from  the  risers. 

When  building  the  pouring  basin  of  green  sand  it  is  usual 
to  place  a  dry-sand  core  at  the  bottom  of  the  basin  at  the  point 
where  the  iron  will  fall  from  the  lip  of  the  ladle,  since  iron 
falling  on  green  sand  may  wash  the  bottom  of  the  basin  into 
the  mold  with  the  first  rush  of  iron.  After  the  pouring  basin 
is  filled  and  the  gates  are  choked,  there  is  little  danger  of  dirt 
entering  with  the  iron.  It  is  also  usual  to  make  that  portion 
of  the  basin,  into  which  the  iron  is  poured,  somewhat  deeper 
than  the  basin  at  the  entrance  to  the  gate. 

The  clamps  are  tightened  on  the  flask  while  the  paste  on 
the  joint  is  still  green,  and  iron  plates  with  a  hole  in  them  are 
set  over  the  top  of  the  post  cores,  the  holes  in  the  plates  co- 
inciding with  the  vent  holes  in  the  cores.  Waste  is  tucked 
around  the  plates  to  prevent  sand  from  falling  into  the  mold 
and  a  rod  of  the  proper  length  is  set  on  top  of  the  plate,  as 
shown  at  V,  Fig.  66.  A  piece  of  pipe  W  is  connected  with  the 
hole  and  sand  is  rammed  around  the  pipe  and  rod  and  a  binder 
X  clamped  across  them  by  means  of  clamps  A  B.  A  wedge  is 
driven  between  the  binder  and  the  rod  V  to  hold  the  chest  cores 
down.  Gases  escaping  from  the  vent  reach  the  air  through 
the  pipes  W.  Both  drag  and  cope  of  the  flask  are  provided 
with  chipping  pieces  which  cause  a  space  to  be  left  between  the 
two  at  the  joint  when  the  mold  is  closed.  Molding  sand  wet 
with  molasses  water  is  rammed  in  these  spaces  to  prevent  iron 
from  breaking  out  when  the  mold  is  poured.  A  space  is  also 
left  around  the  barrel  core  in  order  that  when  setting  the  core, 


DRY-SAND   MOLDS  1 07 

it  may  be  raised  or  lowered  to  give  the  right  thickness  of  cylin- 
der walls.  In  placing  this  core,  paste  was  placed  just  inside  of 
the  edge  of  the  flask,  which  dried  quickly  due  to  the  warmth  of 
the  core.  Before  finally  closing  the  cope,  the  top  of  the  barrel 
core  should  be  covered  with  a  thick  paste,  immediately  adjoin- 
ing the  end  next  to  the  flask.  Thus  with  a  reasonably  tight 
fit  for  the  center  core,  the  paste  will  prevent  any  damp  sand 
rammed  between  the  core  and  mold  from  finding  its  way  into 
the  mold.  The  space  around  the  core  should  be  rammed  with 
sand  and  the  core  barrel  held  down  by  wedges  between  it  and 
the  flange  of  the  flask  on  the  cope  side.  After  the  sand  is 
rammed  in,  a  plate  C,  Fig.  67,  is  rubbed  to  a  bearing,  pegs  of 
iron  D  are  inserted  in  the  holes  in  the  iron  core  barrel,  and 
wedges  E  placed  between  the  pegs  and  the  plate.  This  insures 
against  iron  finding  its  way  out  around  the  core  barrel.  The 
method  of  building  flow-off  troughs  is  shown  at  F,  Figs.  66 
and  67.  The  runner  box  is  next  set  and  weighted  with  pig 
iron.  This  is  the  common  practice,  although  the  author 
recommends  using  a  runner  box  with  flanges  on  the  lower 
edge  by  means  of  which  it  may  be  either  clamped  or  bolted  to 
the  flask. 

Cylinders  molded  in  the  manner  described  above,  may 
weigh  anything  from  a  couple  of  hundred  pounds  to  several 
tons,  and  the  flask  and  other  rigging  must  be  in  proportion 
to  the  weight  of  cylinder  to  be  cast.  Flasks  for  this  work  must 
be  rigid  as  there  is  considerable  strain  brought  on  them  from 
the  molten  iron  in  the  mold  and  it  is  better  to  have  a  flask 
heavier  than  necessary  than  one  which  is  so  light  that  there  is 
danger  of  its  springing  when  the  mold  is  poured.  The  heat  of 
the  iron  must  be  in  proportion  to  the  size  of  the  mold  which  is 
to  be  poured.  A  slack,  dirty  iron  will  seldom  produce  a  satis- 
factory cylinder,  while  a  heavy  cylinder  poured  with  hot  iron 
is  liable  to  be  equally  unsatisfactory.  No  general  rule  can 
be  given  to  cover  this  point  nor  can  one  be  given  to  govern  the 
rate  at  which  the  iron  should  be  poured.  If  iron  is  poured  too 
slowly  in  a  large  cylinder,  cold  shuts  may  result,  while  too  rapid 
pouring  may  wash  certain  portions  of  the  mold  away  and 


IO8  FOUNDRY   PRACTICE 

produce  defective  castings.  Experience  is  necessary  to  obtain 
the  best  results  in  these  two  respects. 

Cylinders  of  this  character  are  usually  poured  at  the 
bottom  and  as  near  as  prudent  to  the  exhaust-chest  post,  as 
imperfections  can  be  repaired  on  the  exhaust  side  which  would 
be  impossible  to  remedy  on  the  steam  side.  As  there  is  usually 
more  room  around  this  post  core,  iron  entering  at  this  point 
has  a  better  chance  to  float  the  dirt  to  the  top  of  the  cope, 
and  it  is  customary  to  allow  an  extra  amount  of  metal  for 
finishing  in  order  to  take  care  of  the  dirt  which  may  rise  in 
these  posts.  Oftentimes,  considerable  excess  metal  is  cast 
here  to  act  as  a  shrinkhead  or  feeder.  When  pouring  begins, 
the  vents  should  be  lighted  and,  when  the  mold  is  filled,  a 
certain  amount  of  iron  should  be  allowed  to  flow  through  some 
of  them.  This  is  done  to  flow  out  any  gas  generated  in  the 
mold  which  may  cause  the  iron  to  kick  away  from  the  surface, 
and  it  will  thereby  be  enabled  to  lie  more  closely  to  the  mold 
and  thus  give  a  better  casting.  If  the  cylinder  is  at  all  large, 
it  should  be  churned  at  the  flow-offs  and  it  may  also  require 
churning  on-  the  port  posts. 

When  pouring  cylinders  of  slide-valve  engines,  the  iron  is 
usually  made  to  enter  at  the  lowest  point  so  that  the  incoming 
iron  will  flow  into  the  iron  already  in  the  mold  and  thus 
restrain  the  dirt  from  entering.  These  cylinders  are  cast  with 
the  valve  seat  down  and  a  sounder  and  cleaner  seat  is  thereby 
obtained,  providing  the  mold  has  been  properly  made. 

MOLDING  PRINTING-PRESS  CYLINDERS  IN  DRY  SAND 

Printing-press  cylinders  are  molded  in  dry-sand  molds  and 
afford  an  interesting  illustration  of  the  use  of  sectional  flasks. 
The  flasks  are  of  iron,  circular,  and  as  many  are  used  superim- 
posed upon  one  another  as  are  necessary  to  give  a  flask  of  the 
requisite  height.  This  class  of  work  is  interesting  in  that  the 
same  pattern  may  be  used  for  cylinders  of  different  lengths, 
the  pattern  being  made  of  sufficient  length  to  answer  for  the 
longest  casting  required.  On  account  of  the  height  of  the 


DRY-SAND   MOLDS  IOQ 

completed  mold  in  this  class  of  work,  it  is  usually  convenient 
to  make  the  mold  in  the  pit  in  which  the  mold  is  poured. 

The  pattern  used  is  shown  in  Fig.  70  and  the  completed 
mold  with  the  cores  in  place  is  shown  in  Fig.  71.  The  sections 
of  the  flask  are  short  cylinders  with  a  flange  at  the  top  and 
bottom,  accurately  machined  so  that  when  the  various  sections 
are  set  one  on  the  other,  the  mold  will  stand  true  and  vertical. 
A  lip  B,  Fig.  71,  is  cast  on  the  interior  of  each  section  to  retain 
the  sand  which  is  rammed  in  the  flask.  Each  section  is  pro- 
vided with  a  pair  of  trunnions  C  set  in  a  boss  D  which  is  pinned 
to  the  flask  with  loose  pins.  Provision  is  made  for  bolting  the 
various  sections  of  the  flask  together  at  the  flanges  and  holes 
are  drilled  in  the  circumference  to  act  as  vents  to  the  mold. 

Referring  now  to  Fig.  70,  the  operation  of  commencing  a 
mold  is  shown.  An  iron  bottom-board  G  is  bolted  to  the  first 
section  of  the  flask  and  is  placed  on  a  solid  bearing  in  the  pit. 
Heap  sand  is  shoveled  into  the  bottom  of  the  flask  and  when 
this  is  at  the  proper  height,  facing  sand  is  rammed  over  it  and 
the  bottom  end  of  the  pattern  is  bedded  into  it.  The  facing 
sand  used  is  a  mixture  of  old  and  new  sand  mixed  in  the  pro- 
portions of  one  part  old  sand,  one  part  .fire  sand,  and  one  part 
coarse  molding  sand.  With  this  is  mixed  flour  in  the  propor- 
tion of  one  part  flour  and  fourteen  parts  sand  mixture.  This 
is  wet  down  with  molasses  water. 

When  the  lower  part  of  the  flask  is  rammed  full,  a  second 
section  is  placed  on  the  first  and  as  there  is  but  little  space 
between  the  pattern  and  the  edge  of  the  flask,  it  is  rammed 
full  with  facing  sand.  A  joint  is  made  at  the  top  of  this  section 
and  the  operation  repeated  until  four  of  these  parts  are  ram- 
med up,  when  a  parting  is  made.  The  remaining  sections  are 
then  placed  and  rammed  up  as  before  until  the  last  section  is 
reached.  In  this  section  a  shrink  head  is  formed  by  cutting 
the  sand  back  to  the  line  H,  Fig.  7 1 .  The  pattern  is  drawn  and 
the  mold  finished,  and,  if  of  large  size,  is  blacked  before  being 
placed  in  the  oven  to  bake. 

In  making  cylinders  up  to  sixteen  inches  diameter  not  more 
than  two  sections  of  the  flask  are  rammed  up  together,  and  in 


HO  FOUNDRY    PRACTICE 

case  of  the  smaller  sizes,  but  one,  before  partings  are  made  as 
they  are  finished,  blacked  and  the  cores  set  more  easily. 

The  core  box  for  making  the  cores  used  in  this  mold  is 
shown  in  Fig.  72.  The  core  projects  on  one  side  as  shown  at  A 
in  order  to  cut  a  slot  in  the  casting.  The  hub  and  arms  of  the 
cylinder  are  at  the  bottom  of  the  core  box.  Three  gate-sticks 
are  set  as  shown  between  the  arms  in  order  to  provide  vents. 
These  must  be  accurately  placed  as,  when  the  cores  are  set  in 
the  mold,  one  above  the  other,  these  vents  must  form  one 
continuous  channel  from  top  to  bottom  of  the  built-up  core. 
Rods  are  set  down  through  the  core  to  strengthen  it  and  three 
staples  are  inserted  between  the  arms,  for  use  in  handling  the 
core  when  it  is  placed.  The  first  core  to  be  set  in  the  mold  is 
made  by  ramming  the  box  full  of  core  sand  and  striking  it  off 
level  with  the  top.  A  plate  is  clamped  on  top,  the  core  box  is 
rolled  over,  the  clamps  removed,  and  the  box  rapped.  What  is 
now  the  toj^of  the  core  box  is  pinned  to  the  sides.  The  pins 
are  removed  and  the  top  lifted  off.  The  sides  of  the  box  are 
split  at  B,  being  held  together  with  clamps  C.  These  are 
knocked  off  and  the  sides  removed.  The  gate-sticks  forming 
the  vents  are  drawn  and  the  core  is  left  on  the  plate  to  be 
finished,  blacked,  and  dried  in  the  oven.  In  making  the  sec- 
tions of  the  core  above  the  first  one,  the  upper  part  of  the  hub  is 
formed  in  the  bottom  of  the  core  as  it  sets  in  the  mold,  by  using 
section  E,  Fig.  73,  in  the  top  of  the  core  box  before  it  is  rolled 
over  on  the  plate.  The  hub  formed  is  filled  with  black  sand 
which  is  removed  after  the  core  is  baked  and  the  space  left  by 
it  is  blacked. 

The  mold  having  been  baked,  the  first  section  of  the 
flask  is  placed  in  the  pouring  pit,  resting  on  the  binder  as 
shown  in  Fig.  71,  and  is  carefully  leveled.  The  first  section  of 
core  is  set  in  this  drag  and  is  also  leveled.  This  core  is 
set  in  core-print  at  the  bottom  of  Fig.  70,  and  is  accurately 
centered.  Around  the  vent  holes  and  also  around  the  vent  in 
the  center  core,  is  placed  a  putty  worm.  The  second  section  is 
placed  on  top  of  the  first  and  the  putty  being  soft  is  flattened 
out  between  the  two  cores  and  forms  a  dam  which  will  prevent 


DRY-SAND   MOLDS 


III 


FIGS.  70-74. — MOLDING  A  PRINTING-PRESS  CYLINDER. 


112  FOUNDRY   PRACTICE 

iron  working  into  the  vents  in  the  cores.  Each  succeeding  core 
is  set  in  this  manner,  being  leveled  as  set.  The  cores  being  in 
place,  the  various  sections  of  the  mold  are  set  around  the  core. 
On  top  of  the  cores  is  placed  a  clay  worm  and  over  this  the 
plate  /.  Two  blocks  of  wood  are  set  on  the  edges  of  the  flask, 
across  which  the  top  binder  K  is  laid.  This  binder  and  that  at 
the  lower  edge  of  the  mold  are  held  together  by  the  stirrup 
R.  Wedges  driven  between  the  upper  binder  and  the  plate 
/  hold  down  the  center  cores.  The  runner  N  is  set  on  top  of 
the  mold,  this  being  of  dry  sand  and  set  as  shown.  Gates  in 
the  bottom  of  this  runner  allow  iron  to  flow  into  the  mold  all 
around  its  circumference.  The  mold  itself  is  left  open  at  the 
top,  rendering  it  easy  to  observe  when  the  mold  is  filled  and  to 
stop  pouring  at  the  proper  time.  This  style  of  runner  box  is 
used  for  many  different  types  of  castings.  It  is  one  of  the  best 
methods  of  getting  clean  iron  into  the  mold,  as  dirt  in  the  iron 
tends  always  to  rise  to  the  surface.  The  iron  from  the  runner 
flows  from  the  bottom  and  therefore  is  the  cleanest  iron,  the 
dirt  remaining  on  the  surface  and  adhering  to  the  sides  of  the 
runner. 

The  hubs  encased  in  the  cores  are  the  last  parts  of  the  cast- 
ing to  cool.  For  this  reason  the  casting,  if  it  is  to  cool  evenly, 
must  be  left  in  the  mold  for  a  considerable  period  of  time  and 
when  removed  must  be  kept  out  of  drafts  until  the  casting  has 
attained  the  temperature  of  the  atmosphere,  otherwise  cracks 
may  be  found  in  various  portions,  particularly  in  the  edges 
where  the  casting  was  stopped  off  by  the  projections  on  the 
core. 

Fig.  75  shows  a  type  cylinder  with  the  cores  set  in  sec- 
tions as  in  the  first  cylinder.  The  hubs,  however,  are  not  tied 
together  as  in  the  first  case  owing  to  some  peculiarity  of  manu- 
facture. The  pattern  used  is  solid  and,  being  of  small  diameter, 
the  sections  of  the  flask  are  rammed  up  one  at  a  time,  and 
parted  at  A,  B,  C,  D  and  E  for  convenience  in  finishing,  black- 
ing, and  setting  the  cores  F.  In  closing  the  cores  over  the  flask, 
the  center  cores  are  first  set  as  before  and  sections  of  the  mold 
closed  around  them.  After  the  first  section  is  in  place,  the 


DRY-SAND     MOLDS 


remaining  sections  are  closed  two  at  a  time,  a  certain  amount  of 
clearance  being  left  between  the  cores  in  the  sides  of  the  mold 
and  the  center  core.  After  the  cores  have  been  set  and  the 
flask  completely  closed,  a  gage  is  run  down  among  the  cores 


FIG.  76  CASTING 
WHEN  CORE  PRINTS 
I  REMOVED 


FIG.  77  ROLL  MOLD  WITH  CORE 


FIG.  78  ROLL  FLASK  TYPE  CYLINDER  MOLD  FIG.  75 


FIGS.  75-80. — CASTING  TYPE  CYLINDERS  AND  ROLLS. 

in  the  mold  to  insure  that  they  are  correctly  placed.  The  mold 
is  poured  with  the  same  kind  of  a  runner  as  before  and  the 
same  rules  should  be  observed  in  pouring. 

Another  style  of  roll  largely  used  is  shown  in  Fig.  76,  while 


114  FOUNDRY   PRACTICE 

adjoining  it,  Fig.  77,  is  the  section  of  the  mold  for  it  with  the 
core  in  place.  The  smaller  sizes  of  these  rolls  are  usually 
molded  on  their  side  in  an  iron  flask,  but  when  poured,  the 
mold  is  set  on  end.  Occasionally  such  molds  are  molded  in 
green  sands,  but  cleaner  and  sounder  castings  are  obtained  by 
the  use  of  dry-sand  molds  in  this  work.  The  core  shown  is  a 
loam  core  (see  Chapter  XI)  and  is  fastened  in  the  mold  at 
the  bottom  by  a  rod  passed  through  a  hole  in  the  gas-pipe 
forming  the  arbor  on  which  the  core  is  built,  the  rod  being 
secured  in  the  flask.  The  core  thus  has  a  chance  to  expand 
upward  when  heated  by  contact  with  the  molten  iron.  After 
closing  the  mold,  it  is  set  upright  and  plumbed  to  insure  its 
being  truly  vertical.  The  various  details  of  runner,  gates,  etc., 
are  shown  in  the  illustration. 

While  many  printing-press  rolls  are  poured  in  the  manner 
described  above,  that  is,  from  the  top,  many  rolls  for  different 
purposes  are  poured  at  the  bottom.  In  this  case,  the  flask 
Fig.  78  is  used.  This  flask  has  a  projection  on  the  front  in 
which  a  gate  can  be  made,  through  which  iron  may  be  poured 
to  enter  the  mold  at  the  bottom.  When  the  flask  is  plumbed, 
the  iron,  entering  the  mold  at  the  bottom,  rises  around  the  core 
evenly,  thus  setting  up  no  uneven  strain  on  any  side  of  the 
core.  For  molding  solid  rolls,  square  flasks  are  sometimes  used, 
the  gates  being  set  in  the  corners  of  the  flask  and  staggered 
somewhat  in  the  various  sections  to  prevent  the  iron  having  a 
straight  drop  the  entire  length  of  the  mold.  A  sprue  is  cut 
from  the  gate  in  one  flask  section  to  that  in  the  next  to  afford 
a  continuous  passageway  for  the  iron.  It  is  best  to  set  a  gate 
in  the  opposite  corner  to  that  down  which  the  iron  is  poured 
and  to  allow  this  second  gate  to  fill,  since,  when  the  roll  is 
cooling,  the  side  on  which  the  gate  is,  through  which  the  iron 
was  poured,  keeps  that  side  of  the  roll  the  hottest  and  thereby 
often  warps  the  roll  in  cooling,  if  but  one  gate  has  been  used. 
By  placing  gates  in  opposite  corners,  both  sides  of  the  roll  are 
kept  equally  hot  and  warping  is  avoided. 

Many  foundries  use  whirl  gates  in  pouring  solid  rolls  (see 
page  24)  to  force  the  dirt  to  the  center  of  the  casting,  whence 


DRY-SAND     MOLDS  115 

it  will  rise  in  a  shrinkhead  or  riser.  In  making  short  rolls  it 
is  often  more  economical  to  make  the  mold  in  a  core  rather 
than  in  sand  and  to  pour  it  on  end.  Thus  a  frame  is  made  and 
the  roll  pattern  molded  in  the  frame  to  form  a  drag,  and  a 
second  frame  is  used  to  form  a  cope.  A  pouring  gate  is 
arranged  down  the  side  and  into  the  bottom  of  the  mold  to- 
gether with  a  riser  for  churning.  The  second  or  cope  frame  is 
gaggered  and  rodded.  The  pattern  is  lifted  with  the  top 
frame  when  it  is  removed,  thus  helping  to  hold  the  sand  in 
place.  If  a  core  is  to  be  used  through  the  center,  it  is  placed 
in  the  lower  half  and  the  top  half  closed  on  it.  If  the  riser  for 
churning  is  arranged  to  be  one-half  in  each  core  forming  the 
mold,  it  will  be  easy  to  see  when  the  cores  are  properly  matched. 
Planks  or  plates  are  clamped  on  each  side  of  the  core  to  hold 
the  two  halves  together  and  it  is  placed  in  a  hole  dug  in  the 
floor  and  sand  rammed  around  it. 

Long  rolls  of  small  diameter  with  a  shaft  in  them,  are  best 
poured  in  an  inclined  position,  the  iron  entering  at  the  bottom 
and  covering  the  lower  end  of  the  shaft  first.  If  bubbling  or 
boiling  occurs  as  the  iron  flows  over  the  shaft,  the  bubble  will 
follow  along  the  shaft  and  enter  a  riser  placed  at  its  high  corner, 
thereby  insuring  sound  metal  in  the  main  casting.  Such  a 
shaft  which  is  to  be  cast  into  a  casting  should  be  tinned  in 
order  to  flux  the  iron  on  it.  Instead  of  placing  the  mold  in  an 
inclined  position  for  long  rolls,  some  foundrymen  favor  the 
use  of  a  large  number  of  gates  on  the  mold  in  order  to  fill  it 
quickly  with  hot  iron,  claiming  thereby  to  obtain  a  sounder 
casting  with  the  core  held  more  easily  in  the  center,  the  iron 
covering  it  quickly  and  burning  it  more  nearly  alike  at  all 
points  and  exerting  an  even  pressure  under  the  core.  Light 
rolls  for  leather  and  cotton  machinery  are  often  poured  in 
this  manner  and  good  results  obtained. 


CHAPTER    XI 

LOAM  MOLDING 

MANY  of  the  larger  and  heavier  castings  are  made  in  what 
are  known  as  loam  molds,  as  this  class  of  mold  is  usually  swept 
up  and  requires  less  pattern  work  than  any  other  class  of  mold. 
A  loam  mold  consists  essentially  of  a  brick  backing  built  up 
on  cast-iron  plates,  the  surface  of  the  bricks  being  covered 
with  loam  which  is  swept  to  the  proper  size  and  shape  to  form 
the  finished  mold.  The  loam  is  baked  on  the  bricks  after  the 
mold  has  been  finished.  Castings  weighing  many  tons  are 
poured  in  this  type  of  mold  and  include  engine  cylinders, 
fly-wheels,  and  similar  heavy  castings. 

In  making  a  loam  mold,  certain  equipment  is  necessary 
and,  in  order  that  the  student  may  understand  the  making  of 
this  equipment,  we  will  assume  that  for  the  mold  which  we  are 
about  to  consider  there  is  none  of  it  immediately  available  and 
that  it  is  necessary  to  make  it  in  the  foundry  before  actual 
molding  is  begun.  We  will  discuss  the  making  of  the  mold 
shown  in  Figs.  82  to  85,  which  is  for  a  large  cylinder.  Before 
commencing  operations,  the  entire  construction  of  the  mold 
must  be  planned  in  advance,  and  provision  made  for  tearing 
away  and  breaking  down  certain  portions  of  the  mold  as  soon 
as  poured  in  order  to  allow  the  casting  to  shrink  while  cooling. 
Green-sand  molds  will  crush  under  the  shrinkage  of  a  casting, 
but  a  loam  mold,  being  stiffened  with  brickwork  and  iron 
plates,  will  not  yield  and  the  casting  will  thereby  be  rup- 
tured in  shrinking  unless  the  mold  is  broken  down  sufficiently 
to  permit  shrinkage. 

The  cylindrical  casting  which  we  are  to  consider  is  seven 

feet  diameter  and  six  feet  long.     It  is  provided  with  flanges 

extending  five  inches  from  the  walls  of  the  cylinder,  each  flange 

two  and  three-quarters  inches  thick.    The  walls  of  the  cylin- 

116 


LOAM   MOLDING  117 

der  are  two  and  one-quarter  inches  thick.  As  there  is  no  equip- 
ment at  hand  for  the  making  of  this  mold  in  loam,  it  is  neces- 
sary for  the  molder  to  provide  himself  with  a  spindle  seat, 
bricks,  sweeps,  sweep  fingers,  carrying  plates,  etc.  A  sketch 
has  been  provided  showing  the  size  and  shape  of  the  casting. 

A  rough  pattern  of  the  spindle  seat,  Fig.  90,  is  made  and  a 
casting  taken  therefrom.  The  spindle,  to  which  the  sweeps  are 
to  be  fastened,  is  formed  of  a  piece  of  cold-rolled  shafting,  two 
and  three-eighths  inches  diameter,  one  end  of  which  is  tapered 
for  a  length  of  one  foot  down  to  one  and  three-eighths  inches 
diameter.  A  number  of  collars,  fitted  with  set  screws,  are 
made  to  fit  snugly  on  the  spindle.  As  the  spindle  is  a  tall  one, 
it  is  advisable  to  make  provision  for  supporting  it  at  the  top  by 
braces  to  the  wall  as  shown  in  Fig.  83.  The  spindle  may  be 
made  either  to  revolve  in  the  seat  or  to  be  fixed.  In  the  latter 
case,  the  sweeps  are  held  at  the  proper  height  on  the  spindle 
by  collars  set-screwed  to  the  shaft  below  them.  The  brace  is 
so  constructed  that  it  may  be  swung  up  out  of  the  way  when 
not  in  use,  or  to  permit  the  lowering  over  the  spindle  of  a 
collar.  The  bracing  is  so  arranged  that  the  spindle  cannot 
move  in  any  direction. 

The  brace  for  the  top  of  the  spindle  is  lowered  into  position 
and  stayed  in  place  with  ropes  and  blocking.  The  spindle 
seat  is  molded  in  the  floor  directly  under  the  center  of  the 
collar  on  the  brace,  its  position  being  determined  by*  a  plumb 
line,  a  fire  brick  being  placed  under  the  center  of  the  hub. 

A  finger  pattern  for  the  sweep  finger  B  has  been  made  and 
castings  from  it  finished  and  bored  out  to  the  size  of  the 
spindle.  One  of  these  fingers  is  placed  on  the  spindle,  which  is 
then  set  in  the  spindle-seat  mold  with  the  end  resting  on  the 
fire  brick.  The  tapered  end  of  the  spindle  having  previously 
been  blackened,  slack  iron  is  poured  into  the  mold,  which  is 
poured  open.  After  the  seat  casting  has  set,  it  is  covered  with 
sand  and  left  until  the  next  morning,  when  a  plank  is  bolted 
to  the  sweep  finger  and  the  spindle  turned  in  the  seat.  Later, 
when  the  seat  Jias  cooled,  the  spindle  is  removed  and  the  seat 
is  properly  set  in  the  sand  for  beginning  molding  operations. 


118  FOUNDRY    PRACTICE 

Before  the  mold  proper  can  be  constructed,  the  plates  on 
which  the  mold  is  to  be  built,  and  which  in  some  cases  are  to 
form  portions  of  the  mold,  must  be  cast.  The  first  plate  to  be 
made  is  the  bottom  or  drag  plate.  A  sand  heap  is  leveled 
under  one  of  the  cranes  and  a  bed  made  on  it.  A  block  of 


FIG.  81. — MOLDING  THE  DRAG  PLATE  AND  CARRYING  PLATE. 

wood  is  bedded  at  the  center  and  with  a  pair  of  trammels  two 
circles  A  and  B,  Fig.  81,  representing  respectively  the  outside 
and  inside  diameter  of  the  plate,  are  traced  on  the  face  of  the 
bed.  A  piece  of  plank  C,  of  somewhat  greatef  thickness  than 
the  plate,  has  one  edge  formed  to  a  section  of  the  outer  circle, 


LOAM   MOLDING  1 19 

and  a  similar  plank  E  is  cut  to  form  a  section  of  the  inner 
circle.  These  two  pieces  of  plank  are  successively  moved 
around  the  circumference  of  the  circle  traced  in  the  sand,  and 
sand  is  rammed  up  against  them  and  struck  off  flush  with  the 
top  of  the  plank.  We  thus  have  formed  in  the  sand  bed  a 
depression  of  the  same  size  and  shape  as  the  desired  drag  plate, 
but  of  somewhat  greater  depth.  As  the  plate  must  be  handled 
by  the  crane  it  is  necessary  to  cast  on  it  four  lugs  D,  which 
quarter  the  circle.  These  lugs  are  formed  by  placing  a  block 
of  wood  of  the  desired  size  and  shape  against  the  segment  C 
at  the  proper  points  on  the  circle  and  ramming  sand  around  it. 
A  flow-off  gate  is  cut  in  the  sand  forming  the  exterior  circle 
around  the  mold  at  the  desired  height  above  the  bottom  of  the 
mold  to  form  the  proper  thickness  of  plate,  in  this  case  two 
and  one-half  inches.  When  the  mold  is  poured,  any  excess 
iron  will  run  off  through  this  gate  and  maintain  the  thickness 
of  the  plate  at  the  desired  point.  Dry-sand  cores  are  placed 
to  form  holes  in  each  of  the  four  lugs  D  and  weighted  down. 
A  pouring  basin  /  is  formed  and  a  screen  built  to  protect  the 
molders  from  the  heat  when  pouring  the  mold.  The  heat  in 
this  case  will  be  intense  as  there  will  be  a  considerable  number 
of  square  feet  of  iron  radiating  heat  at  2,300  deg.  F.  The 
screen  is  formed  by  rods  /  driven  in  the  sand,  against  which 
are  placed  bottom-boards  or  iron  plates  held  in  place  by  other 
rods  driven  in  front  of  them.  It  is  advisable  to  construct  a 
second  pouring  basin  on  the  opposite  side  of  the  mold  from 
the  first  and  pour  into  it  a  small  ladle  of  iron  at  the  same  time 
that  the  larger  basin  is  poured. 

A  cope  plate  is  also  to  be  made,  which  is  similar  in  shape  and 
size  to  the  bottom  plate,  with  the  exception  that  pouring  gates 
must  be  provided  through  which  the  cylinder  mold  is  poured. 
The  cope-plate  mold  is  made  in  the  same  manner  as  was  the 
bottom  plate,  but,  after  the  sand  has  been  built  up  around  the 
outside  and  inside  circles,  a  third  circle  is  struck  in  the  sand  to 
locate  the  pouring  gates.  On  this  circle  cores  C,  Fig.  81,  of  one 
inch  greater  diameter  than  the  pouring  gates  are  set.  Some 
foundrymen  prefer  instead  of  cores  to  use  pieces  of  coke  as  H , 


I2O  FOUNDRY    PRACTICE 

claiming  it  makes  a  rough  hole  which  will  hold  the  loam  around 
the  pouring  gates  better  than  the  core.  As  the  under  side  of 
the  cope  plate  must  be  faced  with  loam,  teeth  must  be  cast  on 
this  face  to  hold  the  loam  when  it  is  swept  on.  These  teeth 
are  formed  by  the  print  M,  consisting  of  a  block  of  wood 
with  the  teeth  formed  on  it,  the  face  of  the  mold  being  printed 
all  over  with  this  block,  as  shown  at  K.  The  finished  cope  ring 
is  shown  in  Fig.  87. 

The  cheek  ring  and  carrying  plates,  Figs.  88  and  89,  are 
molded  and  cast  in  the  same  manner  as  the  cope  plate,  teeth 
being  made  in  the  under  side  to  hold  the  loam.  The  carrying 
plates,  simply  being  required  to  support  the  overhang  of  the 
flange  of  the  cylinder,  are  made  only  five-eighths  inch  thick. 
After  molding  the  carrying  plates,  a  number  of  small  cores 
are  set  across  the  plates  so  as  to  form  a  weak  spot  at  either 
side  enabling  the  plate  to  be  easily  broken  at  the  proper  time. 
The  uses  of  these  various  plates  will  be  explained  as  they  are 
reached  in  the  construction  of  the  mold.  The  brick  used  for 
backing  the  mold  are  common  red  brick,  the  softer  brick  being 
preferred  as  they  are  more  porous  and  will  hold  the  loam 
better  than  the  harder  brick. 

The  loam  mixture  to  be  used  consists  of  New  Jersey  fire 
sand,  a  sand  of  light  yellowish  color,  of  coarse  texture  nearly 
approaching  gravel,  and  having  a  fairly  high  fusing  point,  a 
coarse  molding  sand,  white  pine  sawdust  and  for  bond  dried 
and  ground  Jersey  fire  clay  of  high  plasticity.  These  are  mixed 
in  the  proportions:  four  parts  fire  sand,  one  part  molding  sand, 
one  part  fire  clay,  and  one  part  sawdust  wet  with  water.  The 
sawdust  is  used  to  make  a  porous  open  mixture  which  will 
permit  the  easy  escape  of  gases  when  the  mold  is  poured.  This 
loam  is  thoroughly  mixed  with  a  hoe  and  wet  until  it  is  of  the 
proper  consistency  for  easy  handling  in  the  mold. 

The  various  plates  having  been  made,  the  spindle  seat  is 
set  in  the  floor  and  the  spindle  plumbed  in  it.  The  spindle  is 
then  removed  and  the  bottom  plate  lowered  over  the  seat, 
being  permitted  to  rest  on  timbers  as  shown  in  Fig.  82.  The 
spindle  is  then  replaced  and  a  finger  A  bolted  to  it  and  the  plate 


LOAM    MOLDING  121 

leveled  by  means  of  the  sweep,  which  has  been  previously 
leveled  by  means  of  a  spirit-level.  The  molder  next  places  a 
brick  on  the  plate  and  raises  the  sweep  C  to  a  sufficient  height 
to  permit  the  brick  to  be  laid  in  mortar  on  the  bottom  plate 
and  to  provide  room  for  the  loam  which  is  to  be  swept  on  the 
brick.  The  mortar  used  is  formed  of  sand  and  clay  wet  to  the 
consistency  of  mortar.  Bricks  are  now  laid  on  the  bottom 
plate  to  form  the  seating  as  shown  in  Fig.  82,  being  kept  five- 
eighths  of  an  inch  below  the  edge  of  the  sweep.  After  the  seat- 
ing has  been  built  the  bricks  are  covered  with  the  loam  mixture 
and  trued  off  with  the  sweep.  The  sweep  is  cleaned  off  and 
the  loam  allowed  to  set,  after  which  it  is  given  a  coating  of  slip 
consisting  of  four  parts  of  molding  sand  and  one  part  of  fire 
sand  wet  with  molasses  water.  The  slip  closes  the  pores  of 
the  coarse  sand  and  gives  a  smooth  surface  to  the  mold.  It  is 
allowed  to  dry  after  which  it  is  blackened.  The  seating  is 
made  with  a  slight  slant  at  D  to  provide  clearance  at  the  part- 
ing of  the  cheek.  The  seating  is  sometimes  dried  by  bolting  an 
arm  to  the  spindle  and  hanging  from  it  a  fire  basket  which  is 
swung  around  over  the  seating,  or  at  other  times  by  means  of 
an  oil  burner  when  compressed  air  is  available.  If  there  is 
plenty  of  time,  the  seating  may  be  allowed  to  air-dry  until 
hard  enough  to  carry  its  load,  the  molder  meantime  sweeping 
loam  on  the  carrying  plates.  In  drying  the  seating  by  means 
of  heat,  it  should  be  remembered  that  molding  sand  and  mo- 
lasses water  mixtures  will  burn  very  quickly  and  care  must  be 
exercised. 

After  the  seating  is  dry,  it  is  covered  with  oiled  newspapers 
in  lieu  of  parting  sand  in  a  green-sand  mold,  the  spindle  having 
first  been  removed.  Instead  of  the  newspapers  powdered 
charcoal  mixed  with  water  is  sometimes  used.  The  faces  D 
and  E  of  the  seating  are  covered  with  loam,  after  which  the 
cheek  plate  F,  Fig.  83,  is  lowered,  pricker  side  down,  on  the 
seating  and  loam  is  tucked  between  the  seating  and  the  plate 
on  the  line  D,  Fig.  82,  and  the  plate  leveled.  The  spindle  is 
then  replaced  and  a  second  finger  A,  Fig.  83,  is  attached  to 
it,  sweep  C  then  being  bolted  to  fingers  A  and  B.  Attached  to 


122 


FOUNDRY    PRACTICE 


sweep  C  are  a  number  of  loose  fingers  which  are  removed  as 
the  work  progresses.  This  sweep  as  a  whole  forms  the  inside 
of  the  cheek,  \vhich  in  turn  forms  the  outside  of  the  casting. 


FIQ.82.  SWEEPING  THE  SEATING. 


FIGS.  82-90.  —  MOLDING  A  CYLINDER  IN  LOAM. 


of 


It  is  carefully  plumbed  in  order  to  insure  the  casting 
the  same  diameter  at  the  top  and  bottom.  . 

Referring  now  to  Fig.  83,  at  the  lower  end  of  the  sweep  is 
finger  D  to  form  the  circle  for  the  outside  of  the  lower  flange. 
Bricks  E  are  bedded  in  the  mud  on  cheek  ring  F,  being  set  low 


LOAM   MOLDING  123 

enough  to  permit  loam  to  be  laid  between  their  upper  surface 
and  the  finger  D,  and  by  swinging  the  sweep  around  the  circle 
the  outside  circumference  of  the  flange  is  formed.  The  bricks 
are  loamed  and  built  up  to  the  level  of  the  top  of  the  flange. 
The  loam  is  then  covered  with  slip  and  finished  to  receive  the 
carrying  plate,  after  which  it  is  allowed  to  dry  and  become 
set,  since  it  must  bear  the  weight  of  the  brickwork  on  the 
carrying  plate  and  if  soft  when  the  brickwork  is  built  the 
carrying  plate  will  settle  and  thereby  decrease  the  thickness 
of  the  flange. 

One  of  the  carrying  plates  having  previously  been  covered 
with  loam  on  the  pricker  side,  is  baked  in  the  core  oven.  After 
the  loam  is  hard,  this  plate  is  lowered  on  top  of  the  brickwork 
of  the  mold  already  built  and  centered  from  the  spindle.  Its 
position  is  shown  at  G,  Fig.  83.  The  cheek  is  next  bricked  up, 
as  shown  at  H,  the  various  courses  being  tied  together  and  set 
back  far  enough  from  the  sweep  to  permit  loam  to  be  swept 
on  later.  The  brick  work  is  carried  to  a  point  where  it  is 
necessary  to  set  the  carrying  plate  /,  which  is  to  carry  the 
portion  of  the  mold  which  overhangs  the  vertical  brickwork  H. 
This  plate  is  set  in  loam  mud,  pricker  side  up,  and  the  brick- 
work is  continued  upward  on  it  to  the  thickness  of  the  top 
flange.  Loam  is  then  swept  on  top  of  the  brick  on  the  carrying 
plate  and  on  the  brick  around  the  flange.  Some  molders  will, 
at  this  point,  loam  the  entire  face  of  the  brickwork  already 
built,  but  usually  only  the  part  forming  the  flange  is  done  at 
this  time.  The  loam  is  allowed  to  set,  after  which  the  finger 
K  is  removed  and  the  carrying  plate  L  which  is  to  form  the 
top  of  the  upper  flange  is  placed,  having  previously  been 
loamed  as  was  plate  G.  The  brickwork  is  then  continued  a 
short  distance  above  this  plate  to  form  a  shrinkhead,  being 
kept  back  a  short  distance  in  order  to  give  a  shrinkhead  of 
greater  thickness  than  the  casting.  The  interior  face  of  the 
brickwork  is  now  cleaned  off  and  the  surface  loamed,  the  brick 
being  dampened  if  necessary.  Loaming  is  performed  by  the 
molder  throwing  loam  against  the  surface  by  the  handful  and 
truing  it  off  with  the  sweep.  It  is  evident  that  the  loam  must 


124  FOUNDRY   PRACTICE 

be  worked  to  a  -proper  consistency,  for  if  too  stiff  it  will  not 
adhere  to  the  brick  and  if  too  soft  it  will  sag.  After  truing,  the 
loam  surface  is  coated  with  slip,  usually  by  brushing  it  on  with 
a  molder's  soft  brush,  after  which  the  slip  is  floated  off  with  the 
sweep.  Sweep  and  spindle  are  now  removed  and  the  loam 
and  slip  allowed  to  set,  after  which  blacking  is  applied  to  the 
entire  surface  with  a  swab,  and  slicked  off  with  a  trowel,  being 
finally  finished  with  a  camel's-hair  brush  and  molasses  water. 

By  means  of  the  cross,  shown  in  Fig.  86,  which  is  attached 
to  the  crane,  the  cheek  is  lifted  off,  parting  from  the  seating  at 
M  and  TV.  Slings  from  the  four  extremities  of  the  cross  are 
passed  under  the  four  lugs  on  the  cheek  plate,  the  slings  being 
kept  as  close  to  the  outside  as  possible.  The  cheek  is  then  low- 
ered on  the  carriage  of  the  core  oven,  and,  as  the  loam  on  the 
under  side  of  the  cheek  ring  is  not  dry,  the  ring  is  blocked  up 
under  the  lugs.  The  cheek  is  then  placed  in  the  core  oven  and 
baked  hard. 

The  spindle  is  now  replaced  and  the  center  built.  When 
constructing  the  center  it  should  be  borne  in  mind  that  the 
casting  will  shrink  about  one-eighth  inch  per  foot,  or  in  the 
present  case,  where  the  circumference  of  the  casting  is  about 
twenty-two  feet,  two  and  three-quarter  inches.  Provision 
must  therefore  be  made  for  the  brickwork  to  crush  as  this 
shrinkage  takes  place,  otherwise  the  casting  will  be  ruptured. 
There  is  therefore  provided  a  number  of  loam  bricks,  that  is 
bricks  formed  of  the  loam  mixture  used  in  the  mold,  and  a 
vertical  row  of  these  is  built  into  the  center.  The  fingers  A 
and  B,  Fig.  84,  being  replaced  on  the  spindle,  the  sweep  C  is 
bolted  to  them  and  plumbed,  the  inner  edge  being  set  the  re- 
quired distance  from  the  center  to  give  the  desired  inside 
diameter  of  the  casting. 

The  location  of  the  loam  bricks  is  shown  at  D  in  Fig.  84. 
Oftentimes  when  strength  is  desired  in  the  cheek  a  double 
thickness  of  brick  is  used,  in  which  case  but  a  single  thickness 
may  be  used  in  the  center.  The  cheek  is  required  to  resist  an 
outward  bursting  pressure  in  pouring  and  a  stronger  construc- 
tion than  for  the  center  is  necessary  for  it.  Both  cheek  and 


LOAM    MOLDING  125 

center  must  be  built  so  that  they  will  be  rigid  while  the  mold 
is  being  poured,  but  the  center  must  be  so  constructed  that  it 
will  give  when  the  casting  has  set  and  is  contracting. 

After  bricking  up,  the  center  is  loamed  and  finished  as  was 
the  cheek.  It  is  then  dried  either  in  the  core  oven  or  by  means 
of  a  fire  basket  or  an  oil  flame.  The  covering  or  cope  plate  is 
then  prepared  by  sweeping  loam  on  the  pricker  side,  after  which 
a  circle  is  described  in  the  loam  to  mark  the  location  of  the 
pouring  gates,  which  were  filled  with  loam  when  the  plate  was 
prepared.  While  the  mold  is  drying,  the  curbing,  consisting  of 
sheets  of  boiler  plate  formed  in  a  circle,  is  prepared.  These 
circles  are  made  in  halves  and  for  the  mold  under  consideration 
three  are  required.  If  the  mold  is  to  be  poured  in  a  pit,  how- 
ever, no  curbing  is  necessary.  The  diameter  of  the  curbing  is 
such  that  it  will  completely  encircle  the  mold  outside  of  the 
lugs  on  the  various  plates. 

The  center  being  dried,  it  is  placed  level  on  a  sand  bed 
either  on  the  floor  or  in  a  pit  as  desired  and  the  cheek  ring 
lowered  over  it  to  its  place  on  the  seating.  Before  removing 
the  cheek  from  the  seating  for  drying,  notches  were  cut  in 
both  the  cheek  ring  and  bottom  plate  to  locate  them  with 
reference  to  each  other,  and  in  replacing  the  cheek  these 
notches  are  matched  so  that  in  the  assembled  mold  the  various 
parts  have  the  same  relation  to  each  other  that  they  had  when 
first  built.  The  covering  plate  is  then  set,  being  located  in  its 
proper  position  by  measurement  and  by  looking  through  the 
pouring  gates.  Sometimes  a  seating  is  swept  in  the  cheek  to 
locate  the  cover  plate,  but  in  a  mold  of  the  kind  under  con- 
sideration this  is  usually  unnecessary.  The  cross  is  now  set  on 
the  cover  plate  as  shown  in  Fig.  86  resting  on  blocking,  on 
either  side  of  the  pouring  gates  as  shown  in  Fig.  85.  A  curb 
of  boiler  iron  is  set  against  the  inner  set  of  blocks,  after  which 
slings  are  passed  over  the  ends  of  the  cross  and  under  the  lugs 
on  the  bottom  plate  and  wedged  up,  thus  tying  the  mold  to- 
gether. Wads  of  cotton  waste  are  inserted  in  the  gate  holes 
to  prevent  any  dirt  from  falling  into  the  mold  and  the  first 
section  of  curbing  /  is  set.  Sand  is  rammed  between  this  curb- 


126  FOUNDRY   PRACTICE 

ing  and  the  brickwork,  a  compressed-air  rammer  being  used, 
if  it  is  available.  The  ramming  should  be  done  uniformly, 
preferably  by  a  number  of  men  all  around  the  mold,  so  that 
the  brickwork  will  not  be  strained  unevenly.  After  the  sand 
has  been  rammed  a  short  distance  above  the  first  carrying 
plate,  straw  is  laid  against  the  brickwork  and  sand  rammed 
around  it,  the  straw  forming  a  vent.  The  second  curb  is  ram- 
med as  was  the  first,  but  when  the  third  and  upper  curb  is 
placed  considerable  care  must  be  exercised  in  ramming  sand 
under  the  overhang  and  up  to  the  top  of  the  covering  plate. 
The  wads  of  waste  are  removed  from  the  pouring  gates  and 
gate-sticks  are  inserted.  The  overhang  is  vented  with  a  vent- 
wire  and  the  vents  adjoining  the  curb  are  brought,  by  means  of 
cinders  or  straw,  to  a  point  where  a  gate-stick  may  be  rammed 
in  the  sand  to  form  a  vent  from  the  cinders  or  straw,  after 
which  sand  is  rammed  to  the  top  of  the  curbing  and  the  runner 
built  as  shown  in  Fig.  86.  A  riser  may  be  formed  through  one 
of  the  gate  holes  as  shown,  but  usually  castings  of  this  charac- 
ter are  poured  without  a  riser,  as  it  is  easy  to  tell  when  the 
mold  is  full  by  the  action  of  the  iron  in  the  runner. 

The  casting  being  poured,  the  iron  in  the  runner  is  broken 
as  soon  as  it  has  set  and  steps  are  immediately  taken  to 
provide  for  the  shrinkage  of  the  casting.  The  two  top  sections 
of  curbing  are  unbolted  and  taken  apart.  At  the  same  time 
another  workman  with  a  long  chisel  is  cutting  through  the 
strips  of  loam  brick  built  into  the  center  so  that  the  latter 
may  crush  as  the  casting  contracts.  As  soon  as  the  curbing  is 
removed,  the  wedges  holding  down  the  cross  are  knocked  out 
and  the  slings  removed  from  it.  The  sand  is  cleared  from 
under  the  overhanging  plate  forming  the  upper  flange  of  the 
casting,  and  with  chisel-pointed  bars  the  bricks  are  pried  out 
from  under  this  plate  at  the  points  where  the  rows  of  small 
cores  were  set  when  it  was  made  in  order  to  provide  a  weak 
spot  where  the  plate  could  be  easily  broken.  The  plate  is 
broken  with  a  sledge  and  the  two  halves  pulled  out  from  the 
mold  or  a  course  of  brick  is  removed  from  under  the  plate, 
which  enables  the  casting  to  contract  in  a  vertical  direction 


LOAM   MOLDING  127 

without  danger  of  breaking  off  the  upper  flange.  These  same 
plates  may  be  used  in  a  second  similar  mold  if  desired,  by 
bolting  them  together  across  the  break,  or  by  sweeping  them 
up  separately  in  the  mold. 

In  loam  molds  of  this  character,  plates  of  different  shapes 
are  cast  and  loamed  and  then  used  to  carry  overhanging  parts 
where  the  flanges  or  other  overhang  is  too  wide  to  be  carried 
by  bricks.  Cores  also  are  often  used  for  the  same  purpose, 
especially  where  it  is  necessary  to  cut  the  mold  away  to  permit 
shrinkage  of  the  casting.  Loam  work  is  sometimes  considered 
expensive,  but  in  many  cases  castings  can  be  made  in  loam 
much  more  cheaply  than  in  green  or  dry  sand  when  the  cost 
of  pattern  work,  flasks,  and  necessary  rigging  is  considered. 
Where  a  great  many  castings  are  made  in  loam  the  work  is 
necessarily  done  much  more  cheaply  than  in  foundries  where 
loam  work  is  of  comparatively  infrequent  occurrence. 

In  molding  certain  classes  of  castings  in  loam  a  skeleton  is 
often  furnished  with  some  solid  parts  attached  to  it,  patterns 
being  furnished  for  these  parts.  A  portion  of  the  mold  may  be 
swept  and  a  portion  bricked  up  against  solid  parts  of  the  pat- 
tern. Thus  the  barrel  of  a  steam  cylinder  may  be  swept  and 
the  steam  and  exhaust  chests  formed  by  solid  patterns,  the 
brickwork  being  carried  against  these  parts.  In  this  case  the 
steam  and  exhaust  chests  will  be  tied  together  at  the  top  and 
bottom  by  the  flanges  of  the  cylinder  and  by  the  wrist-plate 
stand  and  any  parts  formed  on  the  barrel  of  the  cylinder.  The 
seating  is  swept  and  the  parts  that  are  to  form  the  lower  end 
of  the  cylinder  are  bricked  and  loamed,  after  which  the  pat- 
tern parts  are  set  and  the  cheek  plate  arranged  on  the  seating 
as  in  the  mold  previously  described.  The  cheek  is  bricked  up 
and  the  pattern  being  well  greased  or  oiled,  the  rounding  por- 
tion of  the  cylinder  is  built  up  to  it,  after  which  loam  is  placed 
against  the  pattern.  Bricks  are  then  dipped  in  water,  rubbed 
in  the  loam,  and  laid  against  the  loam  on  the  pattern,  and  loam 
mud  grouted  in  between  the  various  bricks.  The  sides  of  the 
cylinder  are  continued  upward  and,  to  strengthen  the  brick- 
work, iron  plates  are  built  in  at  intervals.  The  outside  ends 


128  FOUNDRY   PRACTICE 

are  built  last,  as  they  have  to  be  removed  to  allow  the  setting 
of  the  chest  cores.  After  the  cheek  is  built  it  is  hoisted  off  and 
the  center  built  as  in  the  first  mold  considered.  Instead  of 
patterns,  skeletons,  which  are  guides  on  which  sweeps  are  used 
to  form  the  faces  desired,  may  be  bricked  in. 

In  casting  large  fly-wheels  for  engines,  if  there  are  many  to 
be  made,  the  wheel  may  be  hoisted  out  of  the  mold,  leaving  a 
bricked-up  rim  in  good  shape  for  a  second  pouring,  only  the 
loam  face  requiring  repairs.  If  the  loam  is  so  injured  that  it 
is  not  possible  to  repair  it,  it  is  carefully  removed,  the  face  of 
the  brick  cleaned  with  a  wire  brush  and  dampened,  and  the 
proper  thickness  of  loam  swept  on.  Thus  the  time  of  bricking 
up  is  saved.  While  it  was  formerly  customary  to  make  the 
face  of  large  pulleys  in  loam,  they  are  now  often  made  in  green 
sand  or  with  cores. 

Figs.  91-99  show  the  method  of  constructing  the  centers 
of  loam  molds  for  heavy  balance  wheels  and  heavy  gears.  The 
bottom  plate  is  shown  in  Fig.  91,  the  cope  plate  being  similar, 
with  the  exception  that  cored  holes  are  provided  for  risers. 
The  cover  plate  for  the  hub  and  arm  core  box  are  shown  in 
Figs.  92  and  93  respectively.  Fig.  94  shows  grids  which  are 
used  to  strengthen  the  arm  core,  while  Fig.  95  illustrates  a  core 
box  for  forming  the  gear  teeth. 

The  method  of  sweeping  the  seating  is  illustrated  in  Fig. 
96.  If  the  lower  part  of  the  hub  is  to  be  formed  by  means  of 
a  core,  this  is  placed  at  the  center  and  bedded  down  with  a 
spindle  rising  through  the  core-print.  If  it  is  to  be  swept  up  in 
loam  this  operation  is  performed  when  the  seating  is  swept. 
After  the  seating  has  set,  the  gage,  Fig.  97,  is  used  to  set  the 
sweep  A,  Fig.  98,  by  which  the  center  is  formed.  The  brick- 
work is  swept  to  the  proper  height  and  the  cores  A  and  B,  Fig. 
100,  which  form  the  arms  are  placed.  They  are  kept  back  a 
sufficient  distance  to  allow  the  sweep  to  pass  them.  The 
corners  are  usually  rubbed  off  to  permit  the  loam  to  adhere 
later.  The  brickwork,  Fig.  99  F,  is  built  in  between  the  arm 
cores,  being  set  so  that  a  coating  of  loam  can  be  swept  over 
the  face.  As  the  tops  of  the  cores  are  reached,  they  are  bricked 


LOAM     MOLDING 


129 


over,  the  bricks  being  laid  in  a  mixture  of  loam  mud  with  quite 
open  joints.  When  learning  the  bricks  they  should  not  be  dry 
and  better  results  will  be  obtained  if  the  bricks  are  rubbed 
with  loam  before  they  are  laid.  After  learning,  a  coating  of 
slip  is  brushed  on,  after  which  the  face  of  the  mold  is  blackened 


FlS.91.  BOTTOM  AND  TOP  PLATE 
'         OF  COPE  AND  DRAO. 


FJG.S9.  GENERAL  VIEW  OF  MOLD.   TO? 


FIGS.  91-100. — MOLDING  A  FLY-WHEEL  IN  LOAM. 

and  the  whole  center  thoroughly  dried.  While  drying  the 
center,  the  covering  plates  should  be  loamed  and  the  cores  for 
forming  the  teeth  made. 

Before  proceeding  further,  let  us  examine  the  arm  cores, 
which  are  shown  at  B  in  Fig.  100.     These   are  made   with 
grids  to  stiffen  them,  and  in  many  cases  the  grids  are  provided 
9 


130  FOUNDRY   PRACTICE 

with  ears  which  project  beyond  the  edge  of  the  core.  When 
the  two  halves  of  the  core  are  dry  they  are  bolted  together  by 
means  of  these  ears,  thus  forming  a  pipe  through  which  the 
metal  flows  from  the  hub,  where  it  is  poured,  to  the  rim. 

The  center  being  dried  is  replaced  as  shown  in  Fig.  98, 
the  portion  B  of  the  sweep  being  removed  and  replaced  with 
the  piece  D.  The  inner  edges  of  the  tooth  cores  are  set  against 
this  piece  as  it  is  revolved  around  the  spindle.  As  it  is  ex- 
tremely important  that  the  center  be  replaced  after  drying 
in  the  exact  position  in  which  it  was  made,  guides  must  be 
provided  to  insure  its  being  returned  to  this  position.  It  is  bet- 
ter to  dry  the  center  in  place,  even  if  it  is  inconvenient,  rather 
than  to  remove  it  and  dry  it  in  the  oven.  The  tooth  cores 
being  in  place,  a  wall  of  brickwork  is  built  up  back  of  them  and 
dried  out  sufficiently  hard  to  support  the  covering  plate,  which 
is  placed  as  shown  in  Figs.  99  and  100,  and  is  held  in  place  by 
stirrups  or  slings  /  wedged  in  place.  The  center  core  is  set  in 
the  core-print,  the  under  side  being  covered  with  paste  to 
prevent  iron  working  under  it.  The  hub  plate  covering  the 
center  of  the  mold  is  arranged  with  holes  for  pouring  gates 
and  risers  and,  after  loaming,  is  set.  This  is  provided  with  a 
beveled  edge  which  guides  it  to  place  in  a  beveled  seating  swept 
in  the  mold.  It  is  covered  with  paste  where  it  bears  on  the 
center  core.  After  bolting  this  plate  in  place  as  shown,  gate- 
sticks  are  placed,  the  curbing  set,  and  sand  rammed  between  it 
and  the  mold.  The  runner  is  then  made  as  shown  at  L  and 
iron  balls,  each  provided  with  a  handle,  are  placed  over  each 
gate.  In  pouring  the  runner  is  rilled  with  iron,  after  which 
these  balls  are  lifted  and  the  iron  permitted  to  flow  into  the 
mold  from  the  bottom  of  the  pool  in  the  runner.  As  dirt  will 
rise  to  the  surface  of  the  iron,  this  practice  insures  that  only 
clean  iron  will  enter  the  mold. 

After  the  mold  has  been  poured  and  the  iron  set,  usually 
the  next  day,  the  center  covering  plate  should  be  removed  and 
the  core  dug  out.  The  brickwork  should  then  be  removed  from 
between  the  arm  cores,  although  these  will  crush  sufficiently  to 
prevent  breaking  of  the  arms  as  the  casting  shrinks  in  cooling. 


LOAM     MOLDING  131 

When  building  brickwork  for  loam  molds  in  which  a  large 
amount  of  metal  is  to  be  poured,  the  brickwork  is  built  solidly 
around  the  mold  with  cinders  laid  in  between  the  bricks  to 
provide  vents.  It  is  necessary  to  have  a  solid  structure  to 
resist  the  pressure  of  the  metal  and  this  would  be  impossible 
were  the  bricks  to  be  laid  with  rather  open  joints  as  is  done  in 
smaller  molds.  It  is  also  necessary,  however,  that  the  mold  be 
thoroughly  vented  and  this  is  accomplished  by  the  cinders 
which  are  laid  in  between  two  layers  of  loam  mortar  between 
each  course  of  brick.  In  building  the  cheek  of  a  loam  mold  it  is 
advisable  to  lay  whole  brick  on  the  outside  and  small  pieces  on 
the  inside  against  the  loam,  thus  providing  a  large  number  of 
joints  close  to  the  mold  to  act  as  vents.  Conversely,  in  build- 
ing the  center  the  small  pieces  of  brick  should  be  laid  on  the 
outside  and  the  whole  brick  on  the  inside  of  the  center. 

Loam  molds  are  especially  susceptible  to  buckles  and  scabs. 
A  scab  is  formed  by  a  portion  of  the  loam  scaling  from  the 
face  of  the  mold,  leaving  a  cavity  which  forms  a  rough  irregular 
projection  on  the  casting.  The  loam  which  scales  off  fre- 
quently lodges  against  some  other  portion  of  the  mold  and 
thus  forms  a  cavity  in  the  casting.  The  cause  of  this  scaling 
is  usually  the  failure  to  properly  clean  the  face  of  the  brick 
before  loam  is  applied.  It  is  also  frequently  caused  by  the 
use  of  brick  which  have  been  used  for  a  considerable  period 
and  have  become  burned  hard.  The  loam  adheres  with 
difficulty  to  the  glazed  surface  thus  formed.  Another  cause 
of  scaling,  especially  over  flanges,  is  the  failure  of  the  molder  to 
properly  dry  out  the  deep  bed  of  loam,  steam  thus  being  gen- 
erated when  the  casting  is  poured  which  forces  the  loam  from 
the  face  of  the  mold  in  escaping.  A  buckle  is  formed  by  steam 
being  generated  as  above,  but  not  in  sufficient  quantity  to 
rupture  the  loam.  It  may,  however,  expand  and  force  the 
loam  outward  a  short  distance  from  the  surface  of  the  mold 
and  thus  make  a  depression  in  the  casting. 


132  FOUNDRY  PRACTICE 

LOAM  MIXTURES 

It  is  practically  impossible  to  lay  down  any  fixed  rules  for 
the  mixing  of  loam,  as  requirements  for  different  classes  of 
work  vary  greatly,  as  do  the  qualities  of  the  material  obtain- 
able in  different  parts  of  the  country.  However,  the  following 
mixtures  used  by  the  writer  have  given  satisfaction: — 

1 .  One  part  coarse  Jersey  molding  sand 
Two  parts  coarse  Jersey  fire  sand 

One  part  white  pine  sawdust  mixed  with  seven  parts  of  the  above 
mixture.  Mix  with  a  thick  clay  wash  formed  of  clay  of  high  plas- 
ticity. 

2.  Four  parts  fire  sand 

One  part  Jersey  molding  sand 
One  part  ground  clay 
One  part  white  pine  sawdust 

Wet  with  water,  mix  well,  and  allow  to  stand  for  two  days,  after  which 
it  should  be  again  mixed  before  using. 

3.  Mixture  for  a  ten-ton  cylinder  mold. 
One  part  Jersey  molding  sand 
Four  parts  Jersey  fire  sand 

One  part  of  rye  meal  to  twenty  parts  of  the  sand  mixture  wet  with  sour 
beer. 

4.  Mixture  for  a  three-ton  cylinder  mold. 
One  part  Millville  (New  Jersey)  gravel 
One  part  coarse  molding  sand 

Mix  with  water. 

5.  Mixture  for  slip. 

Four  parts  coarse  molding  sand 

One  part  fire  sand 

Wet  with  molasses  water  and  pass  through  a  fine  riddle. 

SWEEPING  LOAM  CORES 

The  illustration  Fig.  101  shows  how  a  loam  core  may  be 
swept  up  on  a  gas-pipe  arbor,  being  built  around  a  hay  rope 
center.  This  core  is  one  that  vents  easily  and  the  gas  escapes 
freely  from  one  end  to  the  other.  A  horse  A  B  with  semi- 
circular notches  in  the  upper  surface  is  used  as  shown.  A  gas- 
pipe  arbor  is  placed  in  corresponding  notches  at  either  end  of 


LOAM     MOLDING 


133 


the  horse,  a  crank  being  set-screwed  to  one  end  of  the  arbor. 
Numerous  holes  are  bored  at  intervals  in  the  gas-pipe  to  allow 
the  escape  of  gases  from  the  core  to  the  interior  of  the  pipe. 
Hay  rope  which  may  be  either  twisted  by  the  molder  or  pur- 
chased from  a  foundry  supply  house  is  wound  on  the  arbor, 
a  thin  cast-iron  plate  F  being  set  at  the  middle  point  of  the 
arbor  to  prevent  the  hay  rope  being  forced  up  toward  the  end 
of  the  core  by  the  pressure  of  the  iron 
when  the  mold  is  poured.  The  hay 
rope  is  wound  firmly  on  the  arbor,  but 
without  sufficient  strain  to  break  it, 
to  approximately  the  shape  of  the 


t±3 

FIG.  101. — SWEEPING  A  LOAM  CORE. 


finished  core  E.  After  the  rope  has  been  wound  on,  coarse, 
clayey  loam  is  rubbed  well  into  the  rope,  a  good  way  being  to 
revolve  the  arbor  and  with  a  round  piece  of  iron  rub  the  loam 
into  the  rope.  After  this  is  done,  loam  should  be  applied 
thickly  to  the  core  and  swept  off  to  the  proper  size  and  shape 
by  revolving  the  core  against  the  sweep  or  strike  G,  which  has 
a  beveled  edge  and  is  used  with  the  beveled  side  up.  The  core 
is  then  dried,  after  which  it  is  replaced  on  the  horse  and  once 
more  revolved,  this  time  a  brick  being  rubbed  lightly  on  its 
face  in  order  to  roughen  it  for  the  coat  of  slip  which  is  swept 
on  the  surface.  The  core  is  then  blackened  and  dried  once 
more  in  the  oven.  The  same  mixtures  of  loam  and  slip  are 
used  in  these  loam  cores  as  in  loam  molds  described  above. 


CHAPTER  XII 

MOLDS  FOR  STEEL  CASTINGS 

THE  subject  of  steel  castings  requires  an  entire  book  in 
itself,  as  it  involves  not  only  questions  of  molding  but  also 
those  of  steel  melting  and  making,  including  open-hearth 
furnace  and  Bessemer  converter  practice.  The  author  pro- 
poses in  this  book  to  treat  only  of  the  problems  of  making 
molds  for  steel  castings  and  for  further  information  regarding 
the  entire  subject  the  reader  is  referred  to  the  excellent  work, 
"Open  Hearth  Steel  Castings,"  l  by  W.  M.  Carr,  and  also  to 
the  splendid  papers,  "Converter  vs.  Small  Open  Hearth,"2 
by  the  same  author. 

Steel  is  a  more  difficult  metal  to  cast  than  iron  as  the 
shrinkage  is  greater,  being  about  one-quarter  inch  per  foot  as 
compared  to  one-eighth  inch  per  foot  for  cast-iron.  It  also  has 
a  shorter  period  of  fluidity  and  expels  a  greater  quantity  of  gas. 
Molds  for  steel  castings  are  made  in  much  the  same  manner  as 
for  iron  castings  of  similar  size  and  shape.  Two  principal 
differences  are  noted,  however,  the  first  being  the  quality  of 
the  sand  used,  and  the  second  the  number  and  size  of  shrink- 
heads  and  risers. 

Molds  for  steel  castings  are  made  of  a  mixture  of  silica 
sand  and  silica  clay,  a  highly  refractory  mixture.  This  is 
necessary  as  the  temperature  of  the  molten  steel  ranges  from 
2,900  to  3,000  degrees  Fahr.  Molding  sand  of  this  character 
requires  the  addition  of  a  certain  amount  of  bonding  material 
to  cause  it  to  hold  together  while  the  mold  is  being  made, 
finished,  and  baked.  Silica  clay  is  used  for  this  purpose,  being 
added  to  the  sand  after  drying  and  grinding.  After  mixing 
together  the  mass  is  wet  with  molasses  water  and  tempered. 

1  The  Penton  Publishing  Co.,  Cleveland. 

2  The  Foundry,  Nov.  and  Dec.,  1907,  Jan.,  1908. 

134 


MOLDS    FOR    STEEL   CASTINGS  135 

Mr.  Carr,  in  "Open  Hearth  Steel  Castings,"  gives  the  follow- 
ing typical  analysis  of  a  molding  sand  for  steel  castings: 

Silica 98.5  % 

Alumina 1 .40% 

Iron  oxide o .  06% 

Lime o .  20% 

Magnesia o.  16% 

Combined  water o.  14% 

Alkalies 0.25% 

The  color  is  often  white  or  slightly  tinged  with  yellow. 
Color  is  not  necessarily  a  guide  to  the  quality  of  molding  sand 
but  is  an  indication.  In  the  same  work  is  given  a  typical 
composition  of  fire  clay  for  use  with  the  above  sand : 


Silica  

60 

to  66 

Alumina  

25 

.  to  20 

Iron  oxide  

0 

tO     2 

o 

to    I 

o 

to    i 

Alkalies.  . 

.  .  o 

tO      2 

Combined  water 7.50  to  10.50% 

Mr.  Carr  also  says,  "The  value  of  fire  clay  depends  largely 
upon  a  low  content  of  alkalies  and  a  freedom  from  carbonates 
of  lime.  Oxide  of  iron  has  a  strong  fluxing  effect,  but  its 
presence  below  three  per  cent  is  harmless."  In  a  certain  steel 
works,  the  face  of  the  molds  for  steel  castings  is  made  from  the 
following  mixture: 

Silica  fire  clay One  part 

Crushed  silica  rock Five  parts 

Silica  sand Eleven  parts 

Dampen  with  molasses  water. 

This  mixture  is  used  for  molding  castings  for  heavy  miter 
gears  and  other  castings  weighing  up  to  1,500  pounds.  For 
smaller  castings  the  same  facing  mixture  is  used,  but  is  adul- 
terated with  burned  sand  from  the  heat. 

The  mold  for  a  steel  casting  is  rammed  up  and  the  pattern 
drawn  in  the  usual  manner.  Flat  surfaces,  however,  if  of  any 


136  FOUNDRY    PRACTICE 

considerable  extent,  are  nailed  after  finishing  by  pushing 
shingle  nails  into  the  surface,  leaving  the  heads  flush  with  the 
face  of  the  mold.  The  nails  will  prevent  the  face  of  the  mold 
from  being  scabbed  or  cut  by  the  fluid  steel  washing  over  it 
when  the  mold  is  filling.  A  coating  of  ground  quartz,  ground 
to  the  fineness  of  flour  and  mixed  with  molasses  water,  is 
applied  to  the  face  of  the  mold  with  a  swab  or  a  soft  brush. 
The  mold  should  then  be  placed  in  an  oven  and  baked.  After 
baking  the  molds  are  closed  and  clamped  for  pouring  in  the 
usual  fashion,  excepting  that  the  steel,  instead  of  being  poured 
over  the  lip  of  the  ladle  as  is  the  case  with  iron  castings,  is 
poured  through  a  gate  in  the  bottom  of  the  ladle,  thus  prevent- 
ing the  slag  floating  on  top  of  the  steel  from  entering  the  mold, 
and  giving  a  cleaner  and  sounder  casting. 

On  account  of  the  great  shrinkage  of  steel  in  cooling  from 
the  liquid  to  the  solid  state,  risers  of  liberal  proportions  must 
be  provided  over  all  the  relatively  massive  portions  of  the 
casting,  to  act  as  reservoirs  of  steel  to  supply  the  casting  with 
liquid  metal  as  it  shrinks  in  the  mold.  Should  these  not  be  of 
ample  size  and  quantity,  cavities  will  result  in  the  finished 
casting. 

Molds  for  steel  castings  must  also  be  made  with  provisions 
for  crushing  wherever  pockets  are  formed  in  the  casting  in 
order  to  take  care  of  the  great  shrinkage.  The  baked  mold  of 
silica  sand  is  an  extremely  rigid  structure,  which  will  offer 
great  resistance  to  crushing,  and  unless  provision  is  made  to 
relieve  this  rigidity  as  the  casting  cools,  it  will  crack  the  cast- 
ing at  the  corners  of  the  pockets,  or  if  the  casting  is  heavy 
enough  to  prevent  cracking,  undesirable  shrinkage  strains  will 
be  set  up  in  it  which  will  have  a  weakening  effect.  It  is  there- 
fore advisable  to  construct  in  the  pocket  of  sand  a  pocket  of 
cinders  which  may  be  formed  by  placing  a  box  in  the  center 
of  the  sand  pocket  which  is  withdrawn  after  the  mold  has  been 
rammed  and  the  cavity  filled  with  cinders,  after  which  the 
mold  is  completed.  Provision,  of  course,  must  be  made  for 
venting  this  pocket  by  one  of  the  methods  previously  described. 
With  this  construction  the  sand  will  be  crushed  into  the  cinder 


MOLDS    FOR    STEEL   CASTINGS  137 

pocket,  as  the  casting  cools,  and  thus  prevent  all  strains  on 
the  latter.  Another  method  of  providing  for  shrinkage  is  to 
construct  the  mold  so  that  certain  portions  of  it  will  break 
down  easily,  as  the  casting  cools  and  contracts.  The  more 
porous  that  either  mold  or  core  can  be  made  for  a  steel  casting 
and  yet  resist  the  action  and  pressure  of  the  molten  metal,  the 
easier  the  gas  can  escape  and  also  the  easier  will  the  mold 
crush  and  thus  prevent  shrinkage  strains  and  afford  sound 
castings. 

Another  feature  which  must  be  borne  in  mind  in  making 
steel  castings  is  that  when  one  part  of  a  casting  is  light,  and 
another  part  adjoining  it  relatively  heavy,  the  light  part  will 
draw  metal  from  the  heavier  part  as  the  former  shrinks  in 
cooling.  Provision  must  be  made  by  means  of  an  ample 
shrinkhead  to  make  up  the  deficiency  of  metal  in  the  heavy 
part,  caused  by  this  action. 

In  making  cores  for  steel  castings  it  should  also  be  borne 
in  mind  that  while  the  same  binder  may  be  used  for  a  core 
for  a  steel  casting  as  for  an  iron  one,  the  sand  used  must  have 
a  much  higher  fusing  point  for  steel  than  for  iron.  While  the 
sand  which  will  give  satisfactory  results  to  the  iron  casting 
may  be  strong  enough  to  resist  the  heat  of  the  steel  so  far  as 
the  shape  of  the  casting  is  concerned,  yet  it  may  fuse  and  ad- 
here to  the  casting,  making  it  difficult  to  remove  from  the  in- 
terior of  the  cored  surface.  Cores  for  steel  castings  are  rodded 
and  vented  the  same  as  for  iron  castings. 


CHAPTER  XIII 

DRY-SAND  CORES 

CAVITIES  in  castings  are  formed  by  cores  which  are  made 
either  of  green  sand,  as  described  in  previous  chapters  on 
molding,  or  of  dry  sand,  mixed  with  a  binder  and  baked  in  an 
oven  to  render  them  hard  and  to  fix  their  shape.  Cores  are 
usually  made  in  a  core  box  of  wood  or  metal,  the  interior  of 
which  is  hollowed  to  the  shape  of  the  exterior  of  the  core.  As 
considerable  gas  is  generated  when  the  cores  are  surrounded 
with  hot  metal  in  pouring  the  mold,  they  must  be  well  vented 
to  permit  the  escape  of  this  gas.  The  cores  are  set  in  the 
mold,  their  location  being  determined  by  core-prints  on  the 
pattern.  The  iron  entering  the  mold  fills  it  and  flowing  around 
the  cores  is/ormed  in  the  desired  shape  with  cavities  or  hollow 
places  the  exact  shape  of  the  cores.  Typical  dry-sand  cores 
are  shown  in  Fig.  102,  and  Fig.  103  shows  the  core  box  for 
making  core  No.  12  together  with  the  method  of  inserting  rods 
in  the  core  for  strengthening  it.  We  will  later  in  this  chapter 
discuss  the  various  operations  of  core  making,  but  we  will  now 
consider  the  various  mixtures  from  which  cores  are  made. 
In  the  various  parts  of  the  country,  the  core  sands  used  vary 
as  regards  their  chemical  analyses  and  range  from  a  very  fine 
sand  to  a  coarse  gravel.  For  very  small  cores,  coarse  molding 
sand  may  be  wet  with  molasses  water,  but  core  sand,  as  the 
term  is  generally  understood,  is  a  very  different  material  from 
ordinary  molding  sand.  In  the  first  place,  molding  sand  has 
bond  and  cohesion  while  core  sand  has  none.  For  making  small 
cores,  a  sharp,  angular-grained  sand  is  preferred,  although 
a  round-grained  sand  with  high  permeability  and  a  large 
amount  of  porosity  will  give  good  results  if  a  good  binder  is 
used  to  hold  it  together.  The  fine  sand  used  in  small  cores  will 
withstand  the  heat  of  the  metal  in  small  castings,  but,  under 
the  influence  of  the  greater  amount  of  heat,  continued  for  a 
138 


DRY- SAND   CORES  139 

considerable  period  in  larger  castings,  the  fine  sand  will  be 
burned  and  the  core  crumbled.  Thus  in  core  making,  as  in 
molding,  coarser  sand  must  be  used  as  the  casting  increases 
in  size,  the  coarser  sands  usually  having  greater  resistance  to 
fusion.  Another  reason  for  the  use  of  coarser  sands  with  large 
castings,  is  that  a  greater  amount  of  gas  is  generated  from  the 
larger  body  of  metal  and  more  provision  must  be  made  for  its 
escape.  The  larger  sands,  being  more  porous,  furnish  this 
provision. 

Inasmuch  as  good  core  sand  has  no  bond  whatever,  and 
water  added  to  it  would  not  cause  it,  after  baking,  to  retain  a 
shape  to  which  it  might  be  molded,  it  is  necessary  to  add  to 
the  sand  some  material  to  act  as  a  binder.  The  binder  not 
only  will  hold  the  core  sand  in  shape  during  and  after  molding, 
so  that  it  may  be  removed  from  the  core  box  and  placed  on  an 
iron  plate  for  baking,  but,  under  the  influence  of  heat,  will  bind 
the  separate  grains  of  sand  together  in  a  firm,  hard  mass,  which 
will  preserve  its  form  when  set  in  the  mold  and  resist  the 
action  of  the  hot  metal.  When  the  core  is  removed  from  the 
casting  it  should  leave  square  corners,  and  hold  in  it  the  exact 
shape  of  the  core  when  it  was  set  in  the  mold. 

There  are  a  variety  of  core  binders  on  the  market,  and  there 
are  others  in  common  use  in  foundries,  the  principal  ingredi- 
ents being  wheat  flour,  rye  meal,  powdered  rosin,  and  linseed 
oil.  Dry  and  liquid  core  binders  must  be  obtained  from 
foundry  supply  houses  or  from  manufacturers.  For  a  core 
which  is  to  be  made  and  set  in  the  mold  a  short  time  before 
pouring,  a  mixture  of  New  England  hill  sand  and  flour  can  be 
used,  mixed  in  the  proportions  of  one  part  flour  to  sixteen  parts 
sand.  This  should  be  tempered  with  water  and  riddled 
through  a  No.  8  sieve  to  remove  lumps.  These  cores  will 
absorb  dampness  somewhat  rapidly  and,  if  the  cores  are  to 
remain  in  the  mold  for  any  length  of  time,  a  mixture  of 
eighteen  parts  sand  to  one  part  flour  wet  with  a  mixture  of 
one  part  molasses  and  sixteen  parts  water  must  be  used.  This 
will  produce  a  harder,  firmer  core  than  before,  which  will  resist 
the  dampness  of  the  mold  for  a  longer  period. 


140  FOUNDRY    PRACTICE 

If  a  core  is  desired  which  will  resist  moisture  still  longer, 
one  part  linseed  oil  to  fifty  parts  sand,  passed  through  a  mixing 
machine,  will  give  good  results.  By  increasing  the  oil  to  one 
part  in  thirty-five  still  better  results  are  obtained.  Hill  sand 
contains  matter  which  is  not  found  in  lake  or  river  sands  and 
these  last  will  absorb  binder  and  produce  cores  with  a  smaller 
quantity  than  the  hill  sand.  When  tempering  the  sand  for  use, 
if  it  is  made  too  damp  the  cores  will  swell  and  be  ruined  when 
baked  in  the  oven.  On  the  other  hand,  the  core  must  be 
sufficiently  wet  with  oil  or  molasses  water  to  bake  right.  The 
degree  of  wetness  necessary  is  impossible  of  description  and 
can  be  learned  only  by  experience. 

For  small  cores  for  brass  or  composition  castings,  a  fine 
sharp  sand  is  necessary.  For  the  cores  in  Fig.  102,  fine  New 
England  hill  sand,  or  lake  sand  of  Pennsylvania  may  be  used. 
New  Jersey  sands  usually  have  a  slight  amount  of  bond  and 
the  finer  sands  require  a  smaller  amount  of  binder  than  usual. 

One  part  flour  or  rye  meal  added  to  sixteen  parts  of  any  of 
the  above  sands  has  been  a  common  mixture  for  many  years 
in  all  parts  of  the  country.  The  amount  of  sand  is  increased 
or  diminished  as  the  cores  increase  or  decrease  in  size.  The 
sand  is  wet  with  a  mixture  of  one  part  molasses  and  sixteen 
parts  water,  and  after  the  cores  are  molded  they  are  baked  to 
a  deep  brown  color. 

Since  the  introduction  of  dry  and  liquid  core  binders, 
eighteen  parts  sharp  core  sand  and  eighteen  parts  old  or  burned 
core  sand,  mixed  with  one  part  of  binder  and  wet  with  mo- 
lasses water  will  give  good  results  for  large-size  cores.  For 
pump  and  small  engine  castings,  a  mixture  of  twenty-five  parts 
sharp  sand  and  twenty-five  parts  burned  sand  and  one  part 
linseed  oil,  thoroughly  mixed  in  a  mixing  machine,  will  make 
excellent  cores.  For  making  a  core  for  a  large  engine  barrel,  a 
mixture  of  four  parts  coarse  New  Jersey  fire  sand  and  two 
parts  of  coarse  molding  sand  to  which  is  added  flour  in  the 
proportion  of  one  part  flour  to  twelve  parts  sand  should  be 
well  riddled  and  wet  with  molasses  water  and  thoroughly 
tempered. 


DRY-SAND   CORES  141 

A  word  regarding  the  qualities  of  the  various  sands  will  not 
be  amiss  at  this  point.  The  New  England  hill  sand  is  large- 
grained  quartzite.  It  resembles  the  lake  sand  largely,  although 
hill  sand  contains  a  certain  amount  of  alumina  while  lake  sand 
is  a  clear  wash  sand.  These  sands  may  be  largely  used  for 
small  cores,  but  to  withstand  high  heat  for  any  length  of  time, 
they  must  be  mixed  with  a  refractory  sand  as  ground  silica 
rock  or  New  Jersey  fire  sand.  River  sands  are  dredged  from 
the  bottoms  of  rivers.  In  the  western  part  of  New  York  is 
found  a  sand  which  resembles  hill  sand  or  river  sand,  but  it  is 
mixed  with  slate  which  fuses  the  sand  and  renders  it  hard  to 
remove  from  castings.  New  Jersey  sands  differ  from  all  other 
in  being  more  refractory.  They  may  be  obtained  in  many 
different  grades  of  fineness  and  are  especially  suited  to  large 
cores  in  heavy  bodies  of  metal. 

In  regard  to  binders  many  experiments  have  been  con- 
ducted to  determine  if  a  portion  of  the  old  core  sand  could  be 
used,  but  it  was  found  that  flour  and  rye  meal  would  not  give 
satisfactory  results  when  used  as  a  binder  in  cores  made  partly 
of  old  sand. 

It  was  found  that  a  core  binder  having  a  pitch  or  tar  body 
would  permit  the  use  of  a  large  percentage  of  old  core  sand  and 
thus  effect  a  saving.  In  order  that  a  core  binder  should  be 
considered  good,  it  must  not  only  bind  the  core  sand  in  the 
green  state  but  bind  it  still  better  when  baked,  so  that  the 
cores  will  hold  their  corners  and  be  blackened  if  necessary,  in 
order  that  the  core  will  stand  the  intense  heat  and  separate 
easily  from  the  casting  when  it  is  cool,  especially  in  the  corners 
and  in  other  portions  hard  to  reach. 

For  core-making  machines,  flour  has  proved  an  unsatis- 
factory binder  as  it  gums  the  machine  and  the  cores  stick.  It 
has  been  found  that  by  using  an  oil  binder  the  sand  could  be 
easily  passed  through  the  tube  of  the  machine  and  satisfactory 
cores  made. 

In  making  a  core  of  the  simpler  form,  such  as  shown  at  i, 
2,  3,  or  4,  Fig.  102,  a  core  box  of  wood  or  metal  is  tucked  or 
rammed  full  of  sand  of  the  proper  mixture  and  the  sand  leveled 


I42 


FOUNDRY    PRACTICE 


off  flush  with  the  top  of  the  box.  The  box  is  then  covered 
with  an  iron  plate  called  a  core  plate,  and  rolled  over  so  that 
the  plate  is  underneath.  The  box  is  rapped  to  free  it  from  the 
sand  core  and  is  then  carefully  lifted,  leaving  the  core  on  the 
plate.  Plate  and  core  are  then  placed  in  an  oven  and  baked. 
The  other  cores  shown  in  Fig.  102  are  more  complicated, 
although  the  general  method  of  making  them  is  the  same.  In 


FIG.  102. — TYPICAL  CORES. 


order  to  form  a  core  of  the  desired  shape  it  is  often  necessary 
to  make  it  in  a  number  of  pieces  and  afterward  fasten  these 
together  by  various  means  according  to  the  size  and  character 
of  the  core.  For  instance,  core  7  is  made  in  halves,  each  half 
requiring  a  special  box.  After  drying,  the  two  halves  are 
cemented  together  with  paste,  the  joint  between  the  two  being 
the  line  X.  The  side  view  of  this  core  is  shown  at  8. 

As  the  sands  and  binder  of  which  the  cores  are  made,  give 
off  large  quantities  of  gas  when  the  molds  are  poured,  great 
care  must  be  exercised,  especially  with  the  larger  cores,  in 
providing  ample  vent  channels  for  the  escape  of  this  gas. 
These  channels  are  arranged  to  lead  the  gas  from  all  parts 


DRY-SAND    CORES  143 

of  the  core  to  a  main  vent  whence  they  are  conducted  into 
vent  channels  in  the  sand  forming  the  mold  itself.  If  the  cores 
are  improperly  vented  the  gases  generated  will  be  imprisoned 
and  may  burst  the  core  with  disastrous  effects  on  the  casting. 
Consider  core  u.  After  the  core  box  is  filled  with  sand  and 
rammed,  it  is  slicked  level  with  the  top,  and  a  channel  is  cut 
lengthwise  in  each  half  of  the  core.  From  this  channel,  holes 
are  formed,  leading  to  the  deeper  parts  of  the  core  to  conduct 
the  gases  to  this  main  vent.  The  two  halves  of  the  core  are 
cemented  together,  the  paste  being  laid  entirely  around  the 
edge  of  one  half  with  the  exception  of  the  space  immediately 
over  the  end  of  the  main  vent.  The  paste  must  not  be  allowed 
to  get  into  the  vent  and  close  it,  or  the  gas  will  be  imprisoned 
in  the  core.  After  the  two  halves  are  cemented  together,  a 
mixture  of  fine  molding  sand  and  molasses  water,  known  in  the 
foundry  as  slurry,  is  rubbed  on  the  joint  between  the  two 
halves  in  order  to  smooth  it  and  avoid  making  a  seam  on  the 
interior  of  the  casting.  This  operation  is  known  as  slurrying 
the  cores.  Referring  to  the  remaining  cores  shown  in  Fig.  102, 
cores  Nos.  9,  n,  13,  14,  and  15  are  made  in  halves  and  after- 
ward pasted  together.  Special  attention  is  called  to  core  9  as 
it  illustrates  the  practice  adopted  where  it  is  impossible  to 
bring  the  main  vent  out  at  the  end  of  the  core.  This  is  often 
the  case  where  iron  is  flowed  over  the  ends  of  the  cores  and  it 
is  necessary  to  bring  the  vent  to  the  most  convenient  point 
for  the  escape  of  gases.  In  the  core  under  consideration,  the 
main  vent  is  brought  out  of  the  core  at  20.  The  iron  flows 
around  the  greater  portion  of  the  core.  That  portion  on  which 
the  numbers  are  inscribed  forms  the  print  resting  in  the  core- 
print  on  the  mold.  At  XX  are  seen  two  staples  through  which 
wire  may  be  threaded  to  hold  the  core  in  place  when  it  is  sus- 
pended from  the  cope. 

While  cores  may  be  of  any  shape,  the  position  they  occupy 
in  the  mold  may  subject  them  to  heavy  strain  and  their  pro- 
portions at  times  may  be  such  that  the  heavier  part  must  be 
supported  by  a  light  portion.  Such  a  case  is  core  12.  With  a 
core  of  this  character,  rods  are  set  in  the  core  when  it  is  made  to 


144 


FOUNDRY    PRACTICE 


strengthen  it.  The  core  box  for  this  core  is  shown  in  Fig.  103 
at  A.  At  B  is  shown  the  opposite  half  of  this  core  box  partially 
filled  with  sand  mixture,  with  the  strengthening  rods  set  in 
position  to  support  the  various  parts  of  the  core.  These  rods 
are  covered  either  with  claywash  or  paste,  to  make  the  sand 
adhere  to  them  and  bake  hard  on  them.  C  is  the.  completed 


FIG.    103.— CORE   Box,   SHOWING  METHOD  OF   RODDING  AND  VENTING 
CORE. 


core,  being  identical  with  that  shown  at  12,  Fig.  102.  At  D 
is  the  finished  casting  showing  the  cavities  formed  by  the 
cores  C. 

The  size  of  the  strengthening  rods  is  increased  with  the 
size  of  the  core,  and  with  the  larger  sizes  the  rods  will  not 
suffice  and  resort  must  be  had  to  grids  or  skeletons  of  cast-iron 
made  to  conform  with  the  shape  of  the  core.  These  are  either 
used  alone  or  in  connection  with  rods.  When  making  these 
grids,  it  should  be  borne  in  mind  that  iron  shrinks  one-eighth 
of  an  inch  per  foot  when  passing  from  the  molten  to  the  solid 
state,  and  in  using  heavy,  strong  grids  in  cores,  these  must  not 
be  allowed  to  approach  close  to  the  sides  or  ends  of  the  cores, 
lest  the  iron  in  the  casting  in  shrinking  bind  on  the  grid  which 
tends  to  expand  with  the  heat,  and  thus  be  cracked  or  broken. 
In  making  these  grids,  a  bed  of  molding  sand  is  usually  made 
in  the  floor  and  the  core  box  laid  on  the  bed  and  its  outline 


DRY-SAND   CORES  145 

traced ;  after  which  the  shape  of  grid  necessary  to  fit  the  inside 
of  the  box  is  cut  out  of  the  sand.  Grids  for  heavy  engine  cast- 
ings, and  the  like,  require  patterns  and  in  some  foundries  a 
special  floor  is  reserved  for  the  molding  of  grids. 

In  order  to  allow  the  larger  sizes  of  cores  to  be  compressed 
by  the  shrinking  of  the  casting,  pockets  are  formed  of  coke  or 
cinders  in  the  core  which  is  made  strong  enough  to  resist  the 
strains  of  pouring  and  yet  sufficiently  weak  to  compress  with 
the  shrinkage  of  the  casting.  These  compression  pockets  also 
act  as  vents  to  carry  gas  from  the  core  and  often  have  vents 
from  more  distant  parts  led  to  them  by  means  of  wax  tapers. 

Wax  tapers  are  made  of  a  thread  coated  with  wax  or 
paraffine  similar  to  a  candle.  They  are  laid  in  the  core  wher- 
ever desired  and  sand  rammed  around  them.  When  the  core  is 
baked  in  the  oven,  the  wax  melts  and  is  absorbed  by  the  sand, 
leaving  a  hole  in  the  core,  through  which  the  gas  escapes 
from  the  surrounding  sand.  By  the  use  of  wax  tapers,  vents 
can  be  made  in  the  core  wherever  desired  with  but  little  trouble 
and  expense.  Wax  tapers  are  used  in  such  cores  as  locomotive 
cylinder  ports  and  others  in  which  it  would  ordinarily  be  diffi- 
cult to  lead  a  vent  around  a  corner.  They  are  also  used  to  a 
considerable  extent  in  very  thin  cores  and  their  use  is  becoming 
quite  general. 

Many  cores  do  not  require  rodding.  Among  these  are 
what  are  ordinarily  termed  stock  cores,  which  are  generally 
round  and  of  different  diameters.  These  are  made  up  in 
quantities  of  varying  length  and  are  cut  off  to  the  length  re- 
quired. When  used  in  a  vertical  position,  they  seldom  require 
to  be  strengthened  with  rods;  but  when  set  horizontally,  rods 
are  required  if  the  cores  are  of  any  length  in  order  to  prevent 
them  breaking  or  springing  when  the  mold  is  poured.  When 
set  in  pulleys,  it  is  usually  best  to  rod  the  core  as  there  is  a 
considerable  length  exposed  to  iron. 

Often  cores  of  irregular  shape,  when  made  in  quantities, 
are  baked  in  what  are  known  as  core  dryers.  This  is  simply  a 
cast-iron  box  of  the  same  shape  as  the  core  in  which  the  core 
is  placed  when  it  is  removed  from  the  core  box,  instead  of 


1 46  FOUNDRY   PRACTICE 

being  set  on  a  core  plate.  The  advantage  of  the  core  dryer  is, 
that  there  is  no  possibility  of  the  core  losing  its  shape,  while 
drying. 

In  recent  years,  the  importance  of  mixing  the  different 
binders  with  the  core  sand  has  been  appreciated,  and  mixing 
machinery  has  been  generally  introduced  in  the  larger  foun- 
dries. In  these  machines,  oil  is  fed  to  the  mixture  automatic- 
ally in  the  desired  proportions,  to  give  the  best  result.  The 
importance  of  preparing  the  sand  for  use  has  long  been  recog- 
nized in  foreign  countries  and  much  attention  has  been  given 
to  it. 

Closely  allied  to  molding  machines,  are  machines  for 
making  cores.  In  fact,  the  development  of  the  molding 
machine,  increasing  as  it  did  the  output  of  foundries,  de- 
manded better  facilities  for  furnishing  cores  in  the  quantities 
required  than  were  possible  with  the  ordinary  hand  equipment 
of  the  core  room.  The  machines  most  commonly  used  are  for 
the  purpose  of  forming  stock  cores,  and  consist  of  a  screw  which 
forces  the  core  mixture  through  a  tube  of  the  proper  diameter 
to  form  the  core.  The  length  of  the  tube  has  a  direct  influence 
on  the  quality  of  the  core,  the  hardness  of  the  finished  core 
being  increased  as  the  length  of  the  tube  is  increased.  Cores 
often  come  from  the  machine  too  hard  for  the  purpose  desired 
and  the  fault  can  be  remedied  by  shortening  the  tube;  the 
machines  are  also  arranged  to  make  triangular,  octagonal,  and 
elliptical  cores  with  satisfactory  results.  The  machines  form 
a  vent  hole  through  the  center  and,  if  desired,  insert  a  rod 
lengthwise  of  the  core  to  strengthen  it.  The  core  comes  from 
the  machine  perfectly  straight  and  is  delivered  on  a  plate  with 
grooves  in  it  to  keep  the  core  in  shape.  Liquid  core  binders  are 
generally  used  with  machines  and  cores  up  to  eight  inches 
diameter  can  be  made  in  certain  types.  The  sand  used  is  as 
a  rule  new  sand,  only  a  small  amount  of  burnt  core  sand  being 
added.  This  is  mixed  with  oil  in  the  proportions  of  forty  or 
fifty  parts  of  sand  to  one  of  oil. 

The  use  of  machines  for  making  stock  cores  has  enabled 
their  length  to  be  increased  to  about  eighteen  inches  instead 


DRY-SAND   CORE'S  147 

of  twelve  as  formerly.  It  has  also  enabled  more  perfect  cores 
to  be  secured.  Formerly,  round  cores  were  made  in  half 
boxes  and  the  halves  pasted  together.  Now  they  are  either 
made  in  whole  boxes  or  by  machine.  Cores  made  in  halves 
and  pasted  together  are  slightly  elliptical  in  cross  section  and 
therefcre  not  as  good  as  the  machine-made  cores. 

Cores,  after  molding,  are  baked  in  any  one  of  the  standard 
core  ovens  which  are  on  the  market.  These  ovens  are  heated 
by  gas,  oil,  or  coke,  as  may  be  most  convenient.  Core 
ovens  for  the  larger-size  cores  are  provided  with  tracks  on 
which  flat  cars,  or  cars  carrying  racks  on  which  the  cores  are 
placed,  may  be  run  into  the  oven  for  baking.  In  certain  types 
of  core  oven,  the  door  is  in  one  piece  and  slides  upward,  being 
counterbalanced.  In  others  it  is  in  the  form  of  a  roller 
curtain.  In  the  smaller  types,  the  doors  are  hung  on  hinges. 
The  core  ovens  of  the  Dickson  Car  Wheel  Co.,  Houston, 
Texas,  represent  good  practice.  The  cores  in  dryers  are  placed 
on  racks  on  a  large  carriage  which  is  run  into  one  of  three 
ovens  by  means  of  a  transfer  table.  The  floor  of  the  oven 
consists  of  iron  plates,  cast  with  two-inch  holes  in  them.  The 
fire  box  is  located  back  in  the  oven  below  the  level  of  the  oven 
floor.  Heat  from  the  fire  is  drawn  under  the  floor  and  passes 
up  through  holes  in  the  plate  as  well  as  from  plates  into  the 
core  oven.  About  two  hours  and  a  half  are  required  to  dry  a 
car  load  of  cores. 

The  even  distribution  of  heat  in  core  ovens  has  been  given 
considerable  attention.  Unevenly  distributed  heat  causes 
considerable  annoyance,  to  say  nothing  of  giving  poor  results 
in  baking  cores.  In  many  ovens  it  has  been  necessary  to  set 
the  cores  as  high  up  in  the  oven  as  possible  in  order  to  dry 
them,  and  in  handling  large  cores  this  has  caused  much  trouble 
and  loss  of  time.  At  the  foundry  of  the  Allis-Chalmers  Co., 
the  large  ovens  are  fired  at  the  back  in  a  specially  built  fire 
box  and  the  heat  drawn  through  an  opening  in  the  back  of  the 
oven.  Special  flues  are  arranged  to  draw  the  heat  to  various 
parts  of  the  oven  as  desired.  Other  designs  include  fire  pots 
placed  in  the  corner  of  the  oven  and  lowered  as  close  as  possible 


148  FOUNDRY    PRACTICE 

to  the  floor.  In  still  other  ovens  a  series  of  flues  are  run  under 
the  floor  and,  in  most  of  the  larger  ovens,  flues  are  provided  to 
carry  off  the  steam  from  the  core.  These  are  closed  at  a  certain 
stage  and  the  heat  confined  to  the  oven. 

While  the  greater  number  of  cores  used  are  made  in  more 
or  less  expensive  boxes,  or  by  machines,  it  is  sometimes 
desirable  to  make  a  core  as  cheaply  as  possible,  few  being 
required.  For  such  cases  core  boxes  often  are  made  separable 


FiG.104-CORE  BOX  FOR  Fia.105-CORE  BOX  FOR 

AN  INEXPENSIVE  CORE  A  COVER  CORE 


CORE  BOX  FOR  A  COVER  CORE  FOR  A  PULLEY 

FIGS.  104-106. 

at  two  diagonally  opposite  corners,  and  having  no  top  or  bot- 
tom, as  shown  in  Fig.  104.  In  use  the  box  is  placed  on  a  core 
plate,  being  held  together  by  the  core-maker  and  filled  with 
core  sand.  After  slicking  off  with  the  trowel,  the  box  is 
removed,  leaving  the  core  on  the  plate. 

Again  cores  known  as  "cake  cores"  or  "cover  cores" 
are  called  for,  these  being  used  as  "covering  cores. "  They  are 
made  in  a  box  consisting  of  a  frame,  of  the  required  size  and 
depth  on  the  inside,  as  Fig.  105.  Sometimes  these  cores  require 
rodding  to  strengthen  them,  and  often  they  are  made  of  a 
strong  mixture,  and  kept  on  hand.  If  for  covering  the  rim  of  a 
pulley  and  shaped  as  shown  in  Fig.  106,  they  are  given  a  coat 
of  blacking  on  one  side,  and  the  larger  cores  are  vented  from 
the  opposite  side.  These  cores  are  used  blackened  side  down. 


DRY-SAND   CORES  149 

Some  cores  are  swept  by  means  of  guides  and  sweeps.  Thus 
a  cylinder  core  of  considerable  size  may  be  swept  in  either  of 
these  ways. 

Fig.  107  shows  a  barrel  or  center  core  made  in  this  manner. 
The  straight  edge  A,  Fig.  108,  is  clamped  to  the  core  plate  B, 
and  the  core  arbor  D  is  placed  in  position,  being  raised  on  the 
core  plate  one  inch  as  seen  at  C,  Fig.  in.  Cinders  or  molding 
sand  E,  Fig.  108,  are  placed  as  shown  and  the  core-sand  mix- 
ture is  rammed  around  -the  arbor  until  it  is  as  high  as  the  top 
of  the  arbor.  Rods  F,  Fig.  108,  are  driven  down  alongside  the 
arbor  to  hold  the  sand  which  is  to  hang  below  the  arbor. 
Sometimes  these  arbors  are  cast  with  prongs  extending  below 
the  backbone  O  of  the  core  arbor  to  hold  the  hanging  sand  to 
the  arbor,  but  arbors  can  also  be  used  without  them,  and  the 
sand  can  be  held  as  above.  Care  should  be  used  that  the  rods 
do  not  come  high  enough  to  interfere  with  the  passing  of  the 
sweep  over  them  when  the  core  is  swept.  At  times,  if  there  is 
a  large  body  of  sand  hanging,  these  rods  are  bent  to  a  hook 
shape  and  used  as  a  gagger  C,  Fig.  no,  one  end  being  hooked 
under  the  arm  of  the  backbone,  and  the  other  end  coming  near 
the  top  of  the  core  as  it  is  swept  forms  an  inverted  gagger,  so 
that  the  sand  is  held  firmly  to  the  arbor.  False  ends,  cut  from 
boards,  shown  at  A  and  B,  Fig.  1 10,  are  now  set  on  edge  on  the 
ends  of  the  arbor  at  F  and  G,  Fig.  108,  and  the  sand  is  rammed 
over  the  arbor  between  these  ends.  The  sweep  A,  Fig.  109,  is 
used  to  shape  the  core,  the  part  C  pressing  against  the  inside 
edge  E  of  straight-edge  D,  as  the  sweep  is  moved  lengthways  of 
the  core.  The  core  is  well  vented  down  to  the  cinders  E,  Fig. 
108,  the  vent  holes  are  filled,  and  core  trued  with  the  strike, 
and  finished  with  the  trowel.  It  is  usually  blacked  while  green 
and  the  blacking  slicked. 

If  the  core  is  long,  one  or  two  gate-sticks  are  set  over  the 
hole  H,  Fig.  108,  to  form  an  opening.  When  the  lower  half 
is  dried  and  rolled  over,  the  top  half  is  dried,  after  which  the 
upper  half  is  rubbed  on  the  lower  half  and  the  core  brought  to 
size.  If  molding  sand  has  been  used  to  form  the  channels  for 
the  vent,  it  is  now  removed.  The  core,  when  found  to  caliper 


150  FOUNDRY   PRACTICE 

the  right  diameter,  is  pasted  together,  and  the  joint  is  slurried 
as  were  the  smaller  cores.  In  addition,  a  long  core  is  bolted 
together  in  the  center  as  well  as  at  the  ends. 

The  top  half  of  the  core  is  made  exactly  as  the  lower  half 
was,  but  as  it  is  not  rolled  over,  there  is  no  hanging  sand,  and 
no  rodding  is  required.  In  rolling  over  the  lower  half  of  a  large 
core,  a  bed  of  molding  sand  usually  is  made  on  the  floor  and 
the  core  rolled  over  on  it.  In  doing  so  care  must  be  exercised 
that  the  edge  is  not  broken.  If  cinders  are  used  for  the  vent, 
they  are  left  as  rammed  up  in  the  core  as  they  form  a  porous 
mass  through  which  the  gas  escapes  easily. 

When  the  core  is  bolted  together  in  the  center,  the  heads 
of  the  bolts  are  covered  with  the  core-sand  mixture,  and  in 
order  to  hold  this  sand  in  the  hole  formed,  spikes  are  driven 
into  the  sides.  These  places  are  blackened  over  and  the  core 
placed  in  the  oven  to  dry  the  paste  and  blacking.  If  the  nole 
in  the  center  of  the  halves  is  large,  it  is  well  to  put  cinders  at 
the  bottom  of  the  core  so  that  the  gases  will  escape  through 
them  from  this  portion.  When  filling  in  the  sand  it  should 
be  vented  down  to  the  cinders;  as,  in  order  to  have  a  sound, 
clean  cylinder  barrel,  it  is  important  that  the  center  core  be 
thoroughly  dry  and  well  vented. 

Another  method  of  venting  a  core  is  to  have  holes  in  the 
end  pieces,  as  D,  Fig.  no,  and  when  the  core  sand  is  rammed 
high  enough  three-eighths  inch  rods  are  placed  through  these 
holes,  extending  about  eight  inches  beyond  the  ends  of  the 
core.  When  the  half  of  the  core  is  finished  the  rods  are  with- 
drawn, leaving  vent  holes  near  the  surface,  but  still  so  far  down 
that  the  iron  cannot  enter  them.  In  some  foundries  these 
ends,  Fig.  no,  are  made  of  cast-iron  and  are  arranged  to  be 
bolted  to  the  core  plate.  When  such  is  the  case,  the  arbor  D, 
Fig.  108,  is  claywashed  and  placed  on  the  plate,  and  ends,  Fig. 
no,  bolted  to  the  plate.  The  ends  A  and  B  have  slots  to  ac- 
commodate the  arbor.  The  sand  is  rammed  up  to  the  proper 
height  on  the  arbor,  hook  rods  or  gaggers  being  used  as  in  the 
first  case,  or  when  the  sand  has  been  rammed  high  enough, 
straight  rods  may  be  driven  down  between  the  arms  on  the 


DRY-SAND     CORES 

FIG.  107 


a 


FIGS.  107-112. — SWEEPING  CORES  ON  AN  ARBOR. 


152 


FOUNDRY    PRACTICE 


arbor.  Rods  to  form  vents  are  run  through  the  holes  in  the 
ends  A  and  B,  these  rods  extending  beyond  the  core.  The  sand 
is  rammed  above  the  ends  over  the  vent-rods  and  is  then  swept 
off  level  by  the  sweep  E,  Fig.  112,  using  the  ends  as  guides. 
The  half  core  is  then  finished,  and  the  strike  laid  down  flat 
over  each  vent-rod,  and  rod  drawn  out,  thus  keeping  the  rod 


FIG.  113. — MAKING  A  FORMED  CORE  BY  MEANS  OF  A  STRICKLE. 

from  breaking  out  through  the  sand  sideways.  The  ends  are 
then  removed. 

The  finished  half  core  is  seen  at  A ,  Fig.  1 1 1 ,  resting  on  the 
core  plate  B,  with  the  core  arbor  C  projecting  from  it.  In 
order  to  hoist  the  core  up  with  the  plate,  holes  D  are  cored  in 
the  plate. 

It  will  be  seen  in  sweeping  cores  that  by  having  a  core  plate 
arranged  in  this  way,  formed  cores  of  different  diameters  may 
be  swept  by  having  the  plate  ends  of  proper  size,  and  having 
the  outline  of  the  core  wished  made  in  the  sweep  or  strike, 
at  times  called  strickles,  as  shown  at  A  and  B,  Fig.  113. 

In  many  of  the  large  foundries  making  steam-engine  cast- 
ings, it  is  the  custom  to  sweep  up  the  center  or  barrel  core  on 


DRY-SAND     CORES 


153 


large  core  barrels  made  of  cast-iron,  thus  effecting  a  saving  of 
core  sand,  labor,  and  time  of  drying.  Some  of  these  barrels 
are  cast  in  halves,  and  when  the  two  have  been  covered  with 
the  core-sand  mixture  and  dried,  they  are  bolted  together.  Fig. 
1 15  shows  one-half  of  the  core  barrel  A  resting  on  core  plate  C, 
with  removable  ends  B  bolted  to  the  core  plate.  An  end  is 


FlG.  114  THE  FINISHED  CORE 

FIGS.  114-118. — BARREL  CORES  MADE  ON  CORE  BARREL  WITH  HORNS. 


shown,  Fig.'n6,  and  D,  Fig.  117,  with  horns  for  holding  the 
sand  to  the  barrel,  and  between  the  horns  are  the  holes 
through  the  barrel  E  for  bringing  the  vent  to  the  inside  of 
the  barrel.  In  use,  the  core  barrel  is  first  given  a  coating  of 
claywash,  and  is  placed  on  core  plate  C,  Fig.  115,  and  the 
ends  B  are  bolted  to  the  barrel  or  plate. 

A  mixture  is  made  of  four  parts  of  coarse  New  Jersey  fire 
sand,  and  two  parts  of  coarse  molding  sand,  to  which  is  added 
flour  in  the  proportion  of  one  flour  to  twelve  of  sand,  and  after 
the  mixture  has  been  well  mixed  and  riddled,  it  is  wet  with 
molasses  water  in  the  proportion  of  one  part  molasses  to  six- 
teen parts  water,  and  thoroughly  tempered.  The  core-maker 
then  uses  it  by  placing  double  handfuls  of  the  mixture  on  the 


154  FOUNDRY    PRACTICE 

core  barrel,  and  with  his  fingers  pressing  it  down  in  between 
the  horns.  In  some  cases  a  bench  rammer  is  used  to  ram  it 
down  on  the  core  barrel,  depending  on  the  length  of  the  horns. 
The  sweep,  Fig.  118,  is  then  used  to  true  the  core  to  the  size 
wished.  In  passing  it  over  the  core  the  first  and  second  time, 
places  will  be  found  requiring  attention  and  hand  work  to 
made  them  solid.  This  is  done  and  the  sweep  passed  over  the 
core  until  it  is  of  tha  right  size,  when  the  core  is  blackened 
and  slicked.  This  half  is  placed  in  the  oven  or  on  a  carriage 
and  the  ends  B  removed  to  be  used  in  sweeping  another 
half. 

When  the  bottom  half  is  dry,  a  piece  of  shafting  is  run 
through  the  holes  in  the  ends,  and  this  half  is  turned  on  the 
bar  F,  Fig.  117,  and  the  joint  is  pasted.  The  top  half  having 
some  of  the  sand  scraped  away  at  the  joint  to  bevel  it,  it  is 
placed  on  the  lower  half  and  the  two  bolted  together  at  G 
and  C,  Fig.  117.  If  the  core  is  of  too  great  length  to  trust  the 
ends  alone  to  hold,  it  is  bolted  together  at  H,  Fig.  115. 

The  joint  is  next  filled  and  pasted,  the  joint  blackened,  and 
the  core  dried  in  the  oven.  When  the  core  is  in  use  in  the  mold, 
the  barrel  expands  and  allowance  must  be  made  for  this,  as 
the  cylinder  is  shrinking  at  the  same  time,  and  the  horns  may 
bind  on  the  inside  of  the  cylinder,  rendering  it  difficult  to 
remove  the  core  barrel. 

In  making  cores  for  small  castings  when  there  is  but  a  small 
amount  of  iron  surrounding  the  core  which  is  made  of  fine 
sand,  the  casting  soon  cools  and  the  core  is  easily  rapped  out, 
leaving  usually  a  smooth  enough  hole  for  ordinary  purposes 
in  the  casting.  But  as  the  cores  increase  in  size  and  the 
amount  of  metal  surrounding  them  increases  in  thickness  and 
weight,  causing  burning  of  the  core,  it  becomes  necessary  to 
protect  the  face  of  the  core  to  prevent  the  iron  from  burning  it, 
or  in  some  cases  from  destroying  its  face  and  producing  a  rough 
casting.  This  is  done  by  coating  the  core  with  a  coat  of  black- 
ing. This  may  be  silver  lead,  wet  with  molasses  water,  or  the 
same  lead  wet  with  clay  water.  Red  New  Jersey  fire-clay  is 
generally  used  in  the  clay  water,  but  blue  clay,  as  found  in 


DRY-SAND     CORES  155 

many  parts  of  the  United  States,  will  answer  if  sufficiently 
refractory.  The  blacking  protects  the  core  from  the  intense 
heat  of  the  iron,  so  that  when  the  casting  is  cleaned,  the  sand  is 
easily  freed  from  it  and  the  casting  is  found  to  be  of  the  shape 
of  the  core  set  in  the  mold.  See  Chapter  XXII,  relative  to 
facing  materials. 


CHAPTER  XIV 

SETTING  CORES  AND  USING  CHAPLETS 

CAVITIES  in  castings  are  formed  by  means  of  cores  of  green 
or  dry  sand,  the  dry-sand  cores  being  made  as  described  in 
Chapter  XIII.  The  dry-sand  cores  are  set  in  the  mold  in  core- 
prints  formed  by  projections  on  the  pattern  which  locate  the 
cores  accurately  in  regard  to  the  rest  of  the  mold.  As  the 
pressure  of  the  iron  in  filling  the  molds  would  tend  to  float  the 
core  to  the  top  of  the  mold,  it  must  be  held  down  by  chaplets, 
as  shown  in  Figs.  120  to  125.  If  the  core  is  long  or  if  the  casting 
is  of  such  shape  that  the  core  is  supported  by  the  core-print 
at  only  one  end,  it  is  necessary  to  use  chaplets  to  support  it 
at  the  opposite  end  or  at  various  points  along  its  length.  In 
Fig.  119  are  illustrated  various  forms  of  chaplets,  each  one  of 
which  has  its  special  uses  and  is  adapted  to  various  classes  of 
work. 

The  chaplets  A  to  Fare  formed  of  perforated  sheet  tin,  and 
will  resist  a  heavier  crushing  stress  than  would  be  imagined. 
The  chaplet  A  with  one  flat  and  one  concave  side  is  used  to 
support  a  round  core  above  a  flat  surface,  or  vice  versa. 
Chaplet  B,  with  one  concave  and  one  convex  surface,  is  used 
with  a  round  core  in  a  cylindrical  mold.  The  chaplet  C  is 
similar  to  the  one  shown  at  F  and  is  used  in  situations  similar 
to  those  requiring  B,  but,  having  four  side  walls  and  being 
larger,  will  resist  a  greater  crushing  stress.  Chaplets  D  and  E 
are  used  either  over  or  under  cores  for  holding  them  down  or 
supporting  them,  E  being  used  in  the  heavier  classes  of  work. 
These  chaplets  are  used  on  the  lighter  classes  of  castings, 
although  they  can  be  used  on  rather  heavy  work  if  desired,  the 
thickness  of  metal  of  which  they  are  formed  being  varied  to 
suit  the  requirements  of  the  case.  The  chaplet  shown  at  H 
is  what  is  known  as  a  water  back  or  front  chaplet  and  is  used  to 
156 


SETTING   CORES   AND    USING   CHAPLETS  157 


FIG.  119. — TYPES  OF  CHAPLETS. 


158  FOUNDRY   PRACTICE 

hold  the  cores  in  the  water  backs  of  stoves.     It  is  made  of 
material  to  which  the  iron  will  readily  flux  when  poured. 

Chaplets  /,  /,  K,  L,  and  M  are  used  on  the  heavier  classes 
of  work  both  to  hold  cores  down,  to  support  them  in  the  mold 
and  to  prevent  their  moving  sideways.  They  are  used  in  con- 
nection with  castings  weighing  many  tons  and  in  various 
combinations  with  one  another.  Chaplets  G  and  /  are  the 
most  commonly  used  types.  They  are  composed  of  a  head 
with  a  shank  or  stem  which  may  be  either  pointed  as  shown  at 
M  or  blunt.  They  are  usually  provided  with  serrations  V, 
near  the  head,  which  will  prevent  the  chaplet  in  any  way 
from  being  driven  or  working  out  of  the  casting  if  by  any 
chance  the  metal  of  the  chaplet  does  not  fuse  with  that  of  the 
casting  when  the  mold  is  poured.  If  the  chaplets  G  or  I  are 
to  be  used  to  support  the  core,  the  stem  is  pointed  and  driven 
through  the  drag  into  the  bottom-board  about  a  quarter  of  an 
inch.  Chaplet  G  is  formed  of  a  stem  with  a  flat  head  riveted  to 
it,  while  chaplet  /  is  made  in  one  piece  by  upsetting  the  stem  to 
form  the  head.  Chaplet  L  is  formed  with  a  pin  projecting 
above  the  head,  which  may  be  inserted  in  holes  in  the  plate  of 
a  chaplet  similar  to  K,  which  has  shoulders  on  the  stem  to 
prevent  the  plate  from  sliding  up  on  it  under  the  pressure  of 
the  entering  metal.  The  stem  of  the  chaplet  L  is  projected 
through  the  sand  of  the  mold  and  either  driven  into  the 
bottom-board  or  wedged  against  the  binder,  as  will  be  de- 
scribed later,  and  thus  transmits  the  pressure  on  chaplet  K 
to  the  flask.  P  is  a  forged  chaplet  used  in  situations  similar  to 
those  in  which  K  is  used.  Larger  heads  may  be  desired  than 
are  possible  on  forged  chaplets  and,  by  using  double-ended 
stems  similar  to  those  used  in  chaplet  K  and  plates  of  different 
sizes  as  N,  a  chaplet  of  any  desired  size  and  shape  may  be  made. 
It  is  advisable,  in  foundries  doing  a  general  class  of  work,  to 
keep  on  hand  a  supply  of  these  stems  and  plates.  /  and  O  are 
small  double-ended  chaplets  used  for  the  same  purpose  as  K, 
while  R,  S,  and  T  are  chaplets  of  small  size,  pressed  out  of  tin, 
which  are  convenient  for  nailing  on  the  side  of  a  mold  and  to 
place  between,  over,  or  under  small  cores. 


SETTING   CORES   AND    USING  CHAPLETS  159 

Chaplets  used  in  steam-,  water-,  gas-,  and  air-cylinder  cast- 
ings are  always  tinned  where  they  come  in  contact  with  the 
molten  iron,  the  tin  acting  as  a  flux  and  causing  the  chaplet 
to  unite  with  the  metal  of  the  casting  and  thus  form  a  joint 
which  will  not  leak  under  pressure. 

Referring  now  to  Figs.  120-122,  we  have  respectively  an 
end  section,  a  plan,  and  a  sectional  plan  of  a  cylindrical  mold 
with  a  cylindrical  core,  which  illustrate  the  method  of  placing 
the  core  and  using  the  chaplet.  Assume  the  pattern  to  be  ten 
inches  diameter  and  the  core  to  have  a  diameter  of  eight  inches, 
the  thickness  of  the  wall  of  the  casting  thus  being  one  inch. 
A  gauge  A  or  B  is  made,  with  the  notch  C  cut  one  inch  deep 
and  sufficiently  wide  to  fit  over  the  edge  of  the  chaplet.  The 
thickness  of  sand  being  ascertained  by  pushing  the  vent-wire 
through  the  mold  where  the  chaplet  is  to  be  set,  there  is  added 
to  this  length  the  thickness  of  metal  of  the  casting  plus  one- 
quarter  inch  which  the  chaplet  will  be  driven  into  the  bottom- 
board,  and  the  stem  is  cut  off  to  the  proper  length  and  pointed. 
The  chaplet  is  then  driven  down  through  the  sand  into  the 
bottom-board  and  the  head  allowed  to  project  one  inch  above 
the  surface  of  the  mold,  this  height  being  determined  by  the 
notch  in  the  gages  A  or  B.  The  bottom  of  the  notch  is  set 
against  the  head  of  the  chaplet  and  the  top  of  the  notch  should 
rest  on  the  surface  of  the  mold.  The  moid  in  question  is  for  a 
column  eight  feet  long.  The  core-prints  at  either  end  of  the 
mold  are  six  inches  long  and,  therefore,  the  core  is  cut  off  to  a 
length  of  nine  feet.  To  prevent  sagging,  it  is  supported  at  the 
middle  by  a  chaplet  placed  in  the  mold  as  described  above. 
To  prevent  the  core  from  moving  sideways,  chaplets  G  are 
placed  on  either  side  of  the  core  as  shown,  a  channel  being  cut 
in  the  sand  at  the  joint  and  a  wedge  driven  between  the  flask 
and  the  blunt  end  of  the  stem,  which  is  cut  about  three-eighths 
inch  short  of  the  distance  between  the  core  and  the  inside  of 
the  flask.  Side  chaplets  and  wedges  are  then  covered  with 
sand  and  the  joint  left  in  its  former  condition. 

The  thickness  of  sand  in  the  cope  over  the  pattern  is  then 
ascertained,  and  to  it  is  added  the  thickness  of  metal  in  the 


l6O  FOUNDRY    PRACTICE 

casting.  A  chaplet  is  cut  off  to  this  length  and  the  end  of  the 
stem  left  blunt.  A  large  vent-wire  is  used  to  make  a  hole 
through  the  sand  at  the  spot  where  the  chaplet  is  to  be  placed, 
and  after  the  chaplet  has  been  inserted  in  this  hole  it  is  held 
in  position  by  pinching  the  sand  around  it  at  the  top  of  the 
cope,  after  which  the  cope  is  closed  on  the  drag.  The  molder 
then  moves  the  chaplet  up  and  down  to  make  sure  that  it 
bears  on  the  core,  after  which  strips  of  wood  /  are  laid  on  the 
edge  of  the  flask  and  a  binder  /  laid  across  the  cope  over  the 
top  of  the  chaplet.  The  binder  /  is  fastened  to  binder  K 
under  the  bottom-board  and  the  two  held  together  with  rod 
bolts  L.  A  wedge  O  is  then  driven  firmly  between  the  binder 
and  the  top  of  the  chaplet  to  hold  the  latter  tightly  against  the 
core,  but  not  so  firmly  as  to  drive  the  latter  into  the  core. 
The  wedge  should  not  be  driven  until  after  the  binders  have 
been  tightened;  otherwise  the  chaplet  might  be  driven  into 
the  core  or  force  it  down  lower  than  desired. 

The  chaplet  E,  Fig.  120,  is  purposely  shown  set  in  the  wrong 
position  in  order  to  illustrate  a  common  fault  in  setting  chap- 
lets,  which  must  be  avoided.  Unless  the  stem  of  the  chaplet  is 
driven  truly  vertical  through  the  sand,  the  chaplet  will  bear 
on  a  single  point  and  when  the  strain  due  to  the  pouring  of 
the  mold  comes  on  it,  it  will  either  bend  or  be  forced  into  the 
core.  In  any  event  the  core  will  rise  more  or  less  in  the  mold 
and  render  the  casting  thinner  on  that  side  than  it  should  be. 
It  is  necessary  that  the  chaplet  have  a  firm  bearing  on  the  core 
and,  to  do  this,  it  must  stand  vertical. 

Fig.  123  illustrates  the  use  of  several  different  types  of 
chaplets.  At  A  is  a  double-ended  chaplet  resting  on  a  piece  of 
a  baked  core  set  in  the  sand  in  the  drag,  placed  there  for  the 
special  purpose  of  holding  it.  At  B  is  a  single-end,  long-stem 
pointed  chaplet,  such  as  we  have  just  described.  In  the  cope, 
at  C,  is  a  chaplet  set  correctly,  while  at  D  is  a  similar  one  set 
incorrectly.  Instead  of  binders  and  bolts,  clamps  are  used  for 
securing  the  cores.  Strips  of  wood  E  are  laid  on  the  edge  of 
the  flask  and  over  them  a  bar  or  piece  of  wood  /  passing  over 
the  tops  of  the  chaplets.  The  clamp  G  is  placed  to  hold  these 


SETTING  CORES   AND   USING   CHAPLETS  l6l 


SECTIONAL  PLAN  OF  MOLD 
Fro.  122 


MOLD  FOR  A  QUARTER  TURN 
PIPE  ELBOW 
FIG.  125 


FIGS.  120-125. — SETTING  CHAPLETS. 


1 62  FOUNDRY   PRACTICE 

bars  E  and  the  bottom-board  F  together,  the  clamp  being 
wedged  in  place  by  the  wedge  H.  Wedges  /  are  inserted 
between  the  top  of  the  chaplets  and  the  bar  /.  This  core  does 
not  require  any  side  chaplets.  It  will  be  observed  that,  this 
mold  being  quite  deep  in  the  cope,  there  will  be  a  considerable 
lifting  tendency  due  to  the  high  head  of  metal.  The  bar  7 
must,  therefore,  be  made  heavy  enough  to  resist  any  tendency 
to  spring;  otherwise  the  core  will  lift  and  iron  may  enter  the 
vent. 

Figs.  124  and  125  show  the  mold  for  a  quarter-turn  pipe 
elbow.  After  the  cope  has  been  made,  an  iron  bar  B  with  a 
lug  A  projecting  from  its  side  is  placed  in  the  top  of  the  cope 
at  the  point  where  the  chaplet  is  to  be  placed,  the  stem  of  the 
chaplet  coming  under  this  lug.  The  stem  of  the  chaplet  is  cut 
to  such  a  length  that  it  will  fit  snugly  against  this  lug  and  pro- 
ject into  the  mold  the  proper  distance  to  give  the  necessary 
thickness  of  metal,  or  the  stem  may  be  cut  short  and  a  wedge 
C  driven  between  the  bar  B  and  the  chaplet. 


CHAPTER  XV 

GATES    AND    GATING 

As  many  castings  required  from  a  single  pattern  are  small, 
it  obviously  would  be  poor  economy  to  mold  each  casting 
separately.  It  would  not  improve  matters  much  to  have  a 
number  of  similar  patterns  separate  from  each  other  and  mold 
them  all  in  the  same  flask.  The  general  practice  in  foundries, 
when  many  similar  small  castings  are  to  be  made,  is  to  string 
them  on  a  gate,  as  it  is  termed.  Saddlery,  shelf  hardware, 
and  small  machine  parts  are  made  in  this  fashion.  This 
method  is  indispensable  in  the  making  of  castings  for  inter- 
changeable machinery,  as  castings  can  be  made  truer  to  pattern 
when  they  are  gated  than  when  they  are  molded  singly. 

The  process  of  gating  is  as  follows:  A  single  master  pattern 
is  made  with  an  allowance,  perhaps,  for  finishing.  From  this 
master  pattern  are  made  the  requisite  number  of  castings  to 
fill  a  flask.  These  castings  are  finished  to  the  pattern  size 
and  are  then  attached  to  a  gate  as  shown  at  A,  B,  C,  D,  and 
£,  Fig.  126.  They  are  arranged,  according  to  the  shape  of  the 
casting,  in  such  a  manner  as  to  permit  the  greatest  possible 
number  to  be  placed  in  a  flask,  and  they  are  also  attached  to 
the  gate  in  the  best  method  for  pouring. 

When  ready  for  use,  a  match-board  is  made  of  plaster  of  Par- 
is or  of  litharge  and  sand  mixed  with  linseed  oil.  This  match- 
board in  appearance  resembles  the  green-sand  match-board 
made  in  the  upset,  shown  in  Fig.  9.  The  match-board  corre- 
sponds to  the  cope  as  the  pattern  is  placed  on  it,  cope  side 
down,  when  molding  is  begun.  The  drag  is  rammed  up  over 
the  match-board  exactly  as  in  any  other  pattern,  pockets 
being  secured  with  nails  or  soldiers  in  the  usual  manner.  As  a 
rule,  however,  patterns  which  are  gated  in  this  fashion,  are 
so  arranged  that  they  may  have  the  sand  riddled  on  them  and 


164 


FOUNDRY    PRACTICE 


be  rammed  up  without  any  other  work.  After  rolling  over  the 
drag,  parting  sand  is  dusted  on  as  soon  as  the  match  is  lifted. 
Should  the  match  be  any  the  worse  for  wear,  a  thin  layer  of 
sand  may  adhere  to  the  pattern.  The  gate  should  then  be 
rapped  slightly  to  jar  this  sand  loose,  after  which  it  may  be 
blown  away  with  the  bellows.  As  a  rule,  however,  it  is  better 


FIG.  126. — METHODS  OF  GATING  PATTERNS. 

to  have  a  new  match-board  made  than  to  work  with  one  with 
which  this  procedure  is  necessary. 

A  small  hole  is  left  at  the  center  of  the  gate,  being  clearly 
shown  in  the  illustration.  The  gate-stick  is  set  in  this  hole  and 
the  cope  is  then  rammed  and  struck  off.  The  gate-stick  is 
withdrawn,  but,  before  lifting  off  the  cope,  the  molder  places 
a  bar  through  the  gate-hole  in  the  pattern  and  raps  it  gently, 
thus  jarring  the  pattern  loose  in  the  cope  and  drag  at  the  same 
time.  By  doing  this,  the  pattern  is  jarred  an  equal  amount 
in  both  cope  and  drag  and  the  finished  casting  will  be  found  to 
be  without  evidence  of  a  seam  or  parting  at  the  joint.  In 
order  that  it  may  be  possible  to  jar  a  pattern  in  this  manner, 


GATES   AND   GATING  165 

the  cope  and  drag  must  be  tight,  that  is,  they  must  have  no 
motion  with  relation  to  each  other,  due  to  the  pins  on  the  flask 
being  loose  in  the  pin-holes.  The  gate  of  patterns  is  then 
drawn  from  the  drag  without  further  rapping.  This  is  usually 
done  by  screwing  a  drawpeg  in  the  rapping  hole,  or  if  the  pat- 
terns are  gated  many  times,  pins  are  provided  in  the  pattern 
for  this  purpose.  Gates  of  patterns  are  seldom  boshed  in  the 
drag  as,  on  the  drag  side,  steady-pins,  shown  at  G,  Fig.  126, 
are  provided.  These  are  round  pins  of  small  diameter,  extend- 
ing below  the  deepest  part  of  the  pattern  to  guide  it  wrhen  the 
pattern  is  drawn  from  the  sand  and  thus  avoid  breaking  the 
sand  and  altering  the  shape  of  the  casting.  The  object  of  ar- 
ranging the  pattern  on  gates  is  to  have  the  pattern,  when 
drawn,  leave  a  perfect  mold,  as  there  must  be  no  stopping  to 
repair  broken  molds  if  the  maximum  output  and  quality  of 
castings  is  to  be  obtained.  Patterns  are  gated  usually  for 
machine  work,  in  which  case  they  are  arranged  so  that  they 
can  be  attached  to  a  vibrator  in  which  compressed  air  is  used 
for  rapping;  a  greater  output  is  thereby  obtained. 

Patterns  are  often  gated  on 'match-plates  as  shown  in  Fig. 
127.  Where  there  are  many  castings  to  be  made,  half  of  the 
pattern  is  mounted  on  one  side  of  the  plate  and  half  on  the 
other,  for  the  cope  and  drag  respectively.  The  plate  itself  is 
usually  of  cast-iron  planed  to  one-quarter  inch  thickness.  In 
mounting  the  patterns,  they  are,  wherever  possible,  finished 
and  the  two  halves  are  drilled  through  so  that  they  will  match 
as  desired.  One-half  of  the  pattern  is  then  placed  in  the  desired 
position  on  the  match-plate  and  used  as  a  jig  for  drilling  the 
match-plate.  The  other  half  of  the  pattern  is  attached  to 
the  opposite  side  of  the  plate  and,  the  holes  in  the  plate  and 
the  two  halves  of  the  pattern  being  aligned,  the  two  halves  of 
the  pattern  will  correspond  exactly  in  position  writh  each  other. 
The  halves  of  the  pattern  are  fastened  to  the  match-plate  by 
pins  extending  through  the  pattern  and  the  plate.  The  gate 
is  also  attached  to  the  drag  side  of  the  plate  as  shown  at  D  in 
Fig.  127.  The  patterns  on  either  side  of  the  match-plates 
A  and  B  in  this  illustration  are  alike,  although  this  is  not 


1 66 


FOUNDRY    PRACTICE 


necessarily  a  characteristic  of  match-plate  patterns.  For 
instance,  the  pattern  C  differs  on  the  two  sides  of  the  plate. 
In  molding  with  match-plates,  the  cope  of  the  flask  is 
placed  directly  on  the  bench,  joint  side  up.  The  match-plate 
is  set  on  the  cope  and  the  drag  on  the  match-plate,  the  pins 
of  the  drag  extending  through  tight  holes  in  the  match-plate. 
The  arrangement  of  the  flask  and  match-plate  is  shown  at  C, 
Fig.  127.  The  drag  is  rammed  up  first,  the  bottom-board 


FIG.  127. — GATING  PATTERNS  ON  MATCH-PLATES. 


rubbed  to  a  bearing,  and  the  entire  flask  rolled  over.  The 
gate-stick  or  gate-pin  is  set,  the  cope  rammed  up,  struck  off, 
and  the  gate-pin  removed.  The  match-plate  is  rapped  and  the 
cope  removed,  being  guided  off  the  pattern  by  the  flask  pins. 
The  match-plate  is  next  removed,  it  also  being  guided  by  the 
flask  pins.  Rapping  the  match-plate  jars  the  sand  alike  in 
cope  and  drag. 

In  foundries  where  compressed  air  is  used,  the  air  is  usually 
piped  to  the  benches,  so  that  in  hand  molding  compressed 
air  may  be  used  for  vibrating  all  match-plate  patterns,  it 
being  possible  to  attach  vibrators  to  any  match-plate.  Match- 
plates  also  are  commonly  used  on  molding  machines.  It  is 
possible,  by  using  match-plates,  to  increase  the  output  of  a 
foundry  to  a  remarkable  extent  when  compared  with  single- 
pattern  molding  handled  one-half  a  pattern  at  a  time.  In 


GATES  AND   GATING  1 67 

making  match-plates,  it  is  usually  best  to  cast  the  match-plate 
with  the  patterns  on  it  at  the  same  time. 

The  process  of  casting  the  match-plate,  with  patterns  on  it, 
is  as  follows:  Consider  the  match-plate  A,  Fig.  128.  The 
patterns,  ten  in  number,  are  split  through  the  center,  forming 
a  cope  and  drag  half  for  each  pattern.  The  drag  halves  are 
placed  on  the  mold-board  in  the  position  shown,  joint  side 
down,  and  the  drag  is  made  and  rolled  over.  The  joint  is 
carefully  made,  and  the  cope  is  rammed  up,  the  gate-stick 
being  set  far  enough  away  from  the  patterns  to  allow  for  mak- 
ing a  plate  around  them  and  gating  into  it.  The  cope  is  lifted 
off  and  carefully  finished,  as  much  parting  sand  being  removed 
as  possible.  An  upset  or  frame,  of  the  thickness  that  is  desired 
for  the  match-plate,  and  of  the  same  size  as  the  flask  with 
which  it  is  to  be  used,  is  placed  on  the  joint  of  the  flask  and 
around  the  patterns,  and  a  frame,  the  size  and  shape  of  the 
match-plate  desired,  is  placed.  This  is  shown  at  B.  The  sand 
is  then  cut  and  roughed  between  the  frames  B  and  the  sides 
and  ends  of  the  upset,  which  has  been  placed  on  the  joint  of 
the  drag  C.  This  keeps  in  position  the  sand  that  is  built  on 
the  top  of  the  sand  joint,  between  the  drag  and  the  frame  B. 
This  sand  is  piled  on  by  hand  and  struck  off  level  with  the  top 
of  the  upset  on  the  joint  of  flask  C,  and  the  frame  B  forming 
the  match-plate,  is  then  drawn  from  the  drag. 

The  process  consists  essentially  in  molding  the  patterns  in 
the  flask  and,  after  drawing  them  from  the  cope  and  drag,  of 
deepening  the  drag  by  adding  one-quarter  of  an  inch  of  sand 
at  the  joint.  A  mold  of  this  character  naturally  requires 
greater  care  in  finishing  than  an  ordinary  mold,  inas- 
much as  it  is  to  form  a  casting,  which  will  be  used  as  a 
master  pattern,  and  any  imperfections  in  this  casting  will 
be  repeated  many  times  over  in  the  castings  made  from  it  as 
a  pattern.  In  pouring  this  mold,  one  side  is  usually  raised 
slightly  as  shown,  by  the  wedge  K,  so  that  the  iron  entering 
the  mold  may  fill  one  side  first  and  flow  up  over  the  face  of 
the  drag  a  little  at  a  time.  With  this  arrangement,  hot  iron 
is  always  flowing  down  to  meet  the  iron  rising  along  the  face 


1 68  FOUNDRY    PRACTICE 

of  the  mold,  and  sharper  castings  are  the  result.  Certain 
shapes  of  castings  are  made  better  by  permitting  the  iron  to 
flow  in  at  the  lower  side  of  the  mold  and  using  a  higher  head 
to  force  it  up  over  the  face  of  the  mold  as  soon  as  possible. 
Further  details  regarding  gating  and  mounting  patterns  on 
match-plates  are  given  in  Chapter  XIX,  on  molding  machines. 

TYPES  OF  GATES 

In  addition  to  the  arrangement  of  patterns,  as  described 
above,  the  term  "gating"  is  also  applied  to  the  method  of  lead- 
ing iron  into  the  mold.  The  arrangement  of  the  gate  is  impor- 
tant, as  on  it  often  depends  whether  or  not  a  clean,  sound 
casting  will  be  obtained.  Fig.  129,  I  and  2  show  the  plan  and 
sectional  elevation  of  a  gate,  arranged  to  clean  the  iron  as  it 
flows  into  the  mold  and  to  prevent  impurities  in  the  casting. 
Referring  to  the  plan,  a  set  gate  is  placed  at  either  corner  of 
the  pattern,  being  set  in  position  when  the  pattern  is  first 
laid  on  the  mold-board.  A  short  distance  behind  the  set  gate, 
are  placed  the  two  skim  gates  A ,  which  are  provided  with  core- 
prints  for  skim  cores.  The  gate-stick  is  placed  in  the  cope  at  B, 
and  when  the  cope  is  lifted  from  the  drag  the  gate  C  is  placed 
in  the  cope.  This  extends  from  the  gate  B  to  each  of  the  skim 
gates  and  a  channel  is  cut  in  the  drag  under  the  skim  gate, 
the  sand  being  softened  where  the  iron  is  to  drop  in  it.  The 
channel  is  cut  still  further  to  connect  the  skim  gate  A  with 
the  set  gate  and  a  core  is  set  in  the  skim  gate,  being  marked 
"skim  core"  in  the  plan.  The  action  of  these  various  gates 
is  as  follows:  Iron  being  poured  fast  enough  to  fill  or  "choke  " 
the  gate  B,  fills  the  gate  C,  which  assists  in  restraining  any 
dirt  in  the  iron.  The  iron  entering  gate  A,  shown  in  the  plan, 
and  flowing  underneath  the  core,  is  skimmed  by  the  core  and 
the  dirt  is  still  further  restrained.  The  round  part  of  the 
set  gate  continues  this  action  and  the  iron,  flowing  through  a 
deep  thin  channel  into  the  mold,  has  but  little  chance  to  carry 
dirt  or  scoria  with  it  into  the  mold.  As  dirt  or  scoria  in  iron 
has  a  tendency  to  rise  to  the  surface,  the  molder  can,  by 


GATES  AND   GATING 


I69 


TOP   VIEW   OF  JOINT, 


' 

^E 

::> 

-0 

1 

1 

SIDE  OF  FLASK  RAISED  FOR  POURING. 
FIG.  128. — CASTING  A  MATCH-PLATE  AND  PATTERNS. 


170  FOUNDRY    PRACTICE 

contriving  his  gates  to  present  pockets  or  skimming  arrange- 
ments similar  to  the  one  described  above,  prevent  a  large 
amount  of  these  impurities  from  passing  into  the  mold  with 
the  iron.  An  arrangement  sometimes  used  is  similar  to  that 
just  described,  with  the  exception  that  the  skim  gates  are 
omitted,  the  set  gates  being  depended  on  to  dam  the  iron 
and  thus  hold  back  the  scoria.  It  is,  however,  necessary  to 
keep  the  gate  B  choked,  inasmuch  as  the  scoria,  being  more 
fluid  than  the  iron,  will  flow  along  the  surface  of  it  if  it  is  given 
a  chance  to  enter  the  cross  gate,  and  thus  get  into  the  mold. 
As  a  general  rule,  a  shallow,  wide  gate  will  permit  more 
impurities  to  enter  the  mold  than  will  a  deep,  narrow  one. 
The  arrangement  of  the  gates,  shown  in  plan  and  elevation 
in  Fig.  129,  i  and  2,  is  shown  in  perspective  at  3,  and  the 
course  of  the  iron  can  be  traced  through  it.  Many  styles  of 
skim  gates  are  on  the  market,  some  of  them  being  patented. 

A  peg  gate  is  shown  in  Fig.  129,  at  4  and  5.  This  consists  of 
a  basin  cut  in  the  cope,  from  which  a  number  of  small  upright 
gates  extend  down  through  the  cope  to  a  basin  cut  in  the  drag, 
whence  a  wide  gate  allows  the  iron  to  enter  the  mold.  Fig. 
129,  6,  shows  a  gate  commonly  used  where  it  is  not  necessary 
that  the  iron  be  kept  particularly  clean.  This  is  mostly  used 
for  such  castings  as  building  plates  and  general  rough  work. 
It  consists  simply  of  the  upright  gate  and  a  channel  cut  from 
the  bottom  of  this  gate  to  the  mold. 

The  horn  gate  is  shown  at  7.  The  uses  of  this  gate  are  many. 
In  pouring  small  gears,  it  is  used  to  bring  the  iron  into  the 
mold,  either  over  or  under  the  teeth  of  the  gear,  as  described 
in  Chapter  II,  and  it  is  also  used  as  a  skim  gate.  As  shown 
in  the  illustration,  the  iron  flows  down  the  upright  gate  and 
then  through  cross  gates  in  either  direction  to  the  horn  gates, 
whence  it  enters  the  mold.  As  the  iron  flows  down  the  semi- 
circular portion  below  the  mold,  the  upper  surface  of  the  gate 
acts  as  a  dam.  The  tendency  of  the  dirt  in  the  iron  will  be 
to  flow  with  it  until  the  gate  is  filled  at  the  bottom,  and  then 
to  back  up  in  that  portion  of  the  horn  gate  adjacent  to  the 
cross  gate,  thus  permitting  clean  iron  only  to  enter  the  mold. 


GATES   AND   GATING 


171 


The  flat  gate  used  by  stove  and  sink  molders  is  illustrated  in 
Fig.  129  at  9.  This  type  of  gate  is  used  for  pouring  thin 
castings,  such  as  stove  tops  and  bottoms  and  similar  classes 


L 


of  work.  On  sinks,  a  number  of  these  gates  are  used  at  one 
time.  As  the  thin  castings  cover  a  large  surface,  it  is  diffi- 
cult to  cut  a  thick  enough  gate  in  the  thin  edge  of  the  casting 


172  FOUNDRY   PRACTICE 

to  properly  fill  the  mold  and  at  the  same  time  one  which  will 
break  away  from  the  casting,  when  cool,  without  breaking 
with  it  a  portion  of  the  casting  itself.  Gates  of  this  character 
are  also  used  with  molds  of  cast-iron  hollow-ware  and  with 
building  facers.  They  may  be  made  of  any  desired  width 
but  are  narrow,  not  exceeding  three  thirty-seconds  of  an  inch 
at  the  point  where  they  adjoin  the  casting.  In  pouring  with 
this  type  of  gate,  the  iron  is  not  poured  directly  into  it,  but 
is  allowed  to  strike  at  about  the  point  marked  A, 

In  molds  where  it  is  desirable  that  the  iron  enter  near  the 
bottom,  such  as  molds  for  steam  cylinders,  the  type  of  gate 
shown  in  Fig.  129,  at  10  and  n,  is  used.  In  making  this  gate, 
two  upright  gates  are  laid  in  the  drag,  four  or  five  inches  from 
the  pattern,  and  between  these  and  the  pattern,  the  gates  C 
are  placed.  When  ramming  up  the  cope,  two  upright  gates, 
somewhat  offset  from  those  in  the  drag,  are  made,  the  relative 
position  of  the  two  being  shown  at  D  and  E.  These  are 
connected  by  the  channel  G  cut  in  the  drag  and  a  pouring  basin 
is  cut  in  the  top  of  the  cope  so  that  both  gates  E  will  be  filled 
at  the  same  time. 

In  pouring  rolls  and  large,  round,  solid  castings,  whirl  gates 
are  used  to  give  the  iron  entering  the  mold  a  whirling  tend- 
ency and  thus  throw  any  dirt  in  it  toward  the  center,  where  it 
can  work  out  of  the  casting  by  means  of  a  riser  on  top  of  the 
casting.  The  whirl  gate  is  usually  made  by  causing  the  metal 
to  enter  the  mold  at  the  circumference  of  the  casting  and  at 
a  tangent  to  it. 

The  gating  of  a  mold  is  a  matter  that  must  be  left  largely 
to  the  judgment  of  the  molder,  depending  on  the  character 
of  the  mold,  as  many  considerations  enter  this  subject.  The 
temperature  of  the  iron  has  considerable  influence  on  the  gat- 
ing, since  hot  iron  will  flow  faster  than  cool  iron.  The  rapidity 
with  which  the  mold  must  be  filled,  depending  on  the  char- 
acter of  castings,  must  also  be  considered.  In  certain  types 
of  mold,  the  iron  must  enter  at  different  places  in  order  to 
fill  all  parts  of  the  mold  properly.  Castings  wnich  have  both 
heavy  and  light  parts  must  often  have  separate  gate?  of 


GATES   AND   GATING  173 

different  sizes  leading  to  the  parts  of  different  weights.  Where 
a  wide  plate  is  to  be  cast,  a  gate  may  be  cut  across  the  entire 
end  of  the  casting,  or  along  one  side,  and  from  this  gate  a  num- 
ber of  ingates  or  sprues  cut  from  it  to  the  casting,  so  that  the 
iron  will  cover  the  entire  surface  of  the  mold  rapidly. 

In  pouring  some  large  molds  with  peg  gates,  from  a  basin, 
it  is  customary  to  use  iron  balls  with  handles,  dipped  in  thick 
blacking  and  dried,  to  stop  off  each  peg  gate,  one  ball  being 
placed  over  each  gate,  when  building  the  green-sand  runner. 
The  iron  is  poured  into  the  basin  and  first  one  ball  and  then 
another  is  lifted  to  permit  the  iron  to  flow  down  through  the 
gates  as  desired.  In  this  way  the  dirt  is  held  in  the  basin, 
clean  iron  flowing  into  the  mold  from  the  bottom  of  the  basin. 


CHAPTER  XVI 

RISERS,  SHRINKHEADS,  AND  FEEDING  HEADS 

A  RISER  is  a  hole  cut  in  the  cope  of  a  mold  to  permit  the 
iron  to  rise  above  the  highest  point  of  the  casting.  It  serves  a 
number  of  purposes.  It  enables  the  molder  to  see  when  the 
mold  is  filled  and  thus  warns  him  when  to  stop  pouring  to 
avoid  straining  the  casting.  It  may  be  used  to  avoid  pocket- 
ing gas  in  a  high  part  of  the  mold  by  being  placed  on  this  high 
point  of  the  casting.  It  may  be  used  as  a.  flow-off ,  being  placed 
at  the  highest  part  of  the  casting.  If  metal  is  permitted  to  rise 
and  flow  out  of  the  mold,  through  this  flow-off,  a  softer  casting 
will  be  produced,  at  the  point  where  the  riser  is  attached, 
than  would  be  the  case  were  the  metal  permitted  to  simply 
rise  up  and  fill  the  mold.  A  riser  placed  near  thin  parts  of 
castings  at  the  joints  of  molds,  connected  to  these  thin  parts 
by  a  gate,  the  iron  being  allowed  to  flow  through  these  gates 
into  the  riser,  will  often  insure  castings  more  nearly  true  to 
the  shape  of  the  pattern  than  would  be  the  case  were  the  riser 
omitted. 

Large  risers  are  used  for  shrinkheads  or  feeding  heads. 
Large  bodies  of  iron,  while  solidifying,  require  a  certain  amount 
of  molten  iron  to  be  fed  to  them  in  order  that  the  casting  may 
entirely  fill  the  mold,  inasmuch  as  iron  shrinks  when  solidifying. 
Feeding  heads  or  large  risers  are  provided  with  large  gates 
between  the  riser  and  the  casting.  The  gate  must  be  of  such 
size  that  the  iron  in  it  will  not  become  solid  before  the  casting 
solidifies.  It  is  essential  that  the  iron  be  permitted  to  flow 
freely  from  the  feeder  head  to  supply  all  deficiencies  due  to  the 
shrinkage  of  the  iron  in  the  mold. 

Castings,  up  to  a  certain  size,  may  be  fed  from  feeder  heads 
by  gravity,  if  the  feeder  or  shrinkhead  is  properly  propor- 
tioned. With  larger  castings,  a  gravity  feed  would  require 
174 


RISERS,    SHRINKHEADS,   AND   FEEDING  HEADS  175 

a  basin  at  the  top  of  the  riser  of  inconvenient  size  and  to  avoid 
this  and  use  a  smaller  riser,  which  may  be  easily  broken  from 
the  casting,  pumping  or  churning  is  resorted  to.  The  molder 
will  place  on  top  of  the  casting,  or  at  times  alongside  of  it, 
a  riser  of  sufficient  diameter  to  permit  the  entrance  of  an  iron 
rod.  This  riser  is  connected  with  the  mold  proper  by  a  larger 
gate.  After  the  mold  has  been  poured,  the  iron  rod  is  inserted 
in  the  riser  and  moved  up  and  down  and  around  the  sides  of 
the  riser.  Molten  iron  is  poured  into  the  ris,er  constantly, 
and,  by  means  of  the  rod,  the  hot  iron  is  kept  in  motion  in 
the  riser  and  gate  and  prevented  from  solidifying  until  after 
the  casting  itself  has  set  or  frozen.  As  the  casting  shrinks  in 
solidifying,  it  draws  on  the  liquid  in  the  riser  for  sufficient  iron 
to  make  up  the  shrinkage  and  fill  the  mold  completely.  The 
operation  above  described  is  known  as  churning  or  pumping. 
When  the  pumping  rod  is  first  pushed  down  into  the  riser,  care 
should  be  taken  not  to  allow  it  to  come  in  contact  with  the 
sand  forming  the  bottom  of  the  mold,  and  thus  tear  up  the  sand 
which  might  find  its  way  back  into  the  mold  and  thus  spoil 
the  casting.  In  moving  the  iron  around  in  the  riser,  the 
opening  kept  clear  should  be  as  large  as  possible.  The  churn- 
ing rod  should  be  struck  every  few  moments  with  a  short  bar 
of  iron  to  prevent  a  ball  of  iron  from  forming  on  it  at  the  point 
where  it  enters  the  riser.  If  the  casting  is  of  such  size  that  a 
considerable  time  is  required  for  churning,  extra  churning  rods 
should  be  provided  for  use  when  the  ball  forms,  as  it  will  do 
eventually.  The  churning  rods  should  be  heated  before  use 
to  prevent  their  freezing  the  riser  when  they  are  inserted  in 
it.  As  the  riser  is  to  furnish  hot  metal  to  the  rest  of  the  cast- 
ing, it  must  be  kept  hot  longer  than  any  other  portion.  In 
churning  large  castings,  it  is  advisable  to  fill  the  top  of  the 
churning  head  with  powdered  charcoal  to  exclude  the  air 
from  the  surface  of  the  iron. 


CHAPTER  XVII 

TREATMENT  OF  CASTINGS  WHILE  COOLING 

OFTEN  castings  which  have  been  molded  and  poured  cor- 
rectly are  found  to  be  warped  and  distorted  on  their  removal 
from  the  sand.  This  may  be  due  either  to  improper  design  or 
to  improper  treatment  of  the  casting  before  it  is  removed  from 
the  sand.  If  a  heavy  part  of  the  casting  immediately  adjoins 
a  light  part,  the  latter  will  solidify  first  and  the  heavy  portion, 
cooling  later,  will  shrink  and  tend  to  draw  away  from  the 
lighter  portion.  If  the  casting  does  not  rupture  in  this 
operation,  strains  may  be  set  up  which  will  warp  the  casting 
out  of  shape  and  thus  render  it  worthless.  This  contingency 
may  often  be  avoided  by  exposing  the  heavier  part  of  the 
casting  to  the  air,  thus  making  it  cool  more  rapidly  while  the 
cooling  of  the  lighter  portion  is  retarded,  the  entire  casting 
thus  becoming  solid  at  about  the  same  time.  Shrinkage 
strains  are  thereby  avoided  and  the  casting  is  removed  from 
the  sand  true  to  pattern.  The  cooling  of  the  lighter  parts  is 
retarded  often  by  covering  them  deeply  with  sand  at  the  same 
time  that  the  heavier  parts  are  exposed  to  the  air. 

Oftentimes  it  can  be  predicted  from  the  shape  of  the  pattern 
the  method  in  which  it  will  cool  and  the  extent  to  which  it  will 
be  distorted  if  allowed  to  cool  normally.  This  distortion  can 
be  avoided  and  the  effects  of  unequal  cooling  counteracted  by 
distorting  the  pattern  in  the  opposite  direction  an  amount 
equal  to  that  distortion  it  would  assume  in  normal  cooling. 
Thus,  in  casting  columns,  the  pattern  is  made  with  the  ends 
relatively  lower  than  the  middle  portion.  The  mold  is  made 
with  the  middle  of  the  column  higher  than  the  ends  which  cool 
last.  They  are  thus  thrown  up  as  the  casting  cools  and  if  the 
right  amount  of  camber  has  been  given  to  the  pattern  the 
column  will  be  perfectly  straight  when  cold.  The  same 
176 


TREATMENT   OF   CASTINGS    WHILE   COOLING  177 

method  is  followed  in  casting  the  copings  for  the  top  of  brick 
walls.  Cornice  work  for  buildings  is  usually  molded  with  a 
camber  in  the  same  manner.  The  castings  are  usually  made 
with  lips  at  the  edges,  for  bolting  together,  combined  with 
moldings.  The  lips  on  the  edges  of  the  plates  are  often  on 
opposite  sides  of  each  edge,  and  the  pattern  is  arranged  on  the 
mold-board  crooked  in  the  opposite  direction  from  which  it  will 
crook  when  cooling.  Thus  one  edge  will  be  crooked  in  one 
direction  and  the  other  in  the  opposite  direction  and  when  the 
casting  is  cold  these  edges  will  be  straight  and  parallel.  Lathe 
beds,  up  to  fourteen  feet  in  length,  are  molded  with  a  camber, 
as  the  ends  tend  to  rise  in  cooling.  A  lathe  bed  thirty  feet 
long,  however,  is  so  heavy  that  the  casting  in  shrinking  will 
not  lift  the  ends  and  therefore  these  beds  are  cast  with  the 
center  down. 

Many  castings  of  different  lengths  must  be  kept  covered  at 
the  ends  in  cooling  while  the  sand  is  dug  away  from  them  at  the 
center.  Often  if  a  casting  is  of  such  size  and  shape  that  it  must 
be  left  overnight  in  the  sand  it  is  advisable  to  dig  the  sand 
away  from  around  the  gates.  This  is  to  permit  the  casting  to 
shrink  while  cooling  without  being  held  by  the  gates,  and 
thereby  having  a  piece  at  or  near  the  gates  torn  out  or  a  crack 
started  due  to  the  rigidity  of  the  structure  held  in  one  position 
by  the  gates. 

In  certain  classes  of  work  it  is  not  sufficient  to  retard  the 
cooling  of  the  thin  parts.  An  artificial  supply  of  heat  must 
be  provided.  Such  a  case  is  the  casting  for  a  disk  crank  of  a 
stationary  engine  which  consists  of  an  engine  crank  surrounded 
by  a  web,  the  crank  and  counterbalance  being  hidden  on 
the  inside  by  a  plate.  This  casting  is  molded  with  the  plate 
face  down  and  the  pockets  of  sand  to  form  the  crank  and 
counterbalance  are  lifted  out  with  the  cope.  After  pouring, 
the  cope  is  lifted  as  soon  as  possible  and  the  sand  dug  out  of 
these  pockets,  leaving  only  enough  sand  in  them  to  protect  the 
casting.  Molten  iron  is  then  poured  into  these  pockets  or  pig 
beds  and  covered  with  sand,  after  which  the  cores  in  the  hub 
and  crank-pin  hole  are  dug  out.  Thus  the  thinner  portions 


178  FOUNDRY    PRACTICE 

are  continuously  supplied  with  heat  until  the  entire  casting 
has  cooled  uniformly.  If  this  precaution  is  not  adopted,  the 
crank  disk  will  either  be  found  cracked  when  it  is  taken  from 
the  sand  or  strains  will  be  set  up  which  will  cause  the  disk 
to  fail  when  it  is  forced  on  the  engine  shaft  by  hydraulic 
pressure. 

Castings  of  U-shaped  section  should  be  gated  together  at 
the  top,  as  in  cooling  the  tendency  is  for  the  bow  to  cool  first 
and  thus  draw  the  legs  of  the  casting  apart,  which  tendency  is 
resisted  by  the  gates,  which  cool  first.  If  it  is  impossible  to 
gate  the  casting  in  this  manner,  the  bow  portion  should  be 
uncovered  at  the  earliest  possible  moment  while  the  legs  of  the 
U  should  be  kept  covered  and  their  cooling  retarded. 

Pulleys  for  power  transmission,  with  thin  rims,  should  have 
the  center  core  removed  as  soon  as  the  metal  has  set,  especially 
if  the  pulley  is  of  large  diameter.  Often  a  pulley  that  is  re- 
quired in  a  hurry  is  removed  from  the  sand  while  the  hub  is  still 
red-hot.  This  condition  of  affairs  will  cause  a  heavy  strain 
on  the  arms  and  will  frequently  pull  them  from  the  rim.  To 
avoid  this  condition  the  sand  is  dug  away  from  the  cope  over 
the  hub  as  soon  as  possible  and  water  poured  into  the  hole 
formed  by  the  core.  The  rim  and  arms  are  kept  covered  and 
the  heat  retained  in  them  as  long  as  possible.  Large  fly-wheels 
and  balance-wheels  are  often  cast  with  the  hubs  split  by  means 
of  cores,  the  rim  being  cast  solid.  As  the  rim  contracts  the 
two  parts  of  the  hub  are  forced  together  and  cracking  of  the 
arms  and  rim  is  avoided.  Conversely  to  the  above  cases,  if 
the  rim  is  heavy  and  the  center  comparatively  light  the  rim 
must  be  uncovered  and  cooled  more  rapidly  than  the  center. 

Plates  cool  first  at  the  edges  and  frequently  are  found 
checked.  This  condition  can  be  cured  by  removing  the  cope 
as  soon  as  the  casting  has  solidified,  knocking  the  sand  from 
the  cope  down  on  the  casting  and  cutting  channels  in  it  diago- 
nally across  the  plate  from  opposite  corners,  thus  permitting 
the  center  to  cool  in  advance  of  the  edges. 

Where  castings  are  made  with  heavy  rigid  cores  in  them 
they  may  be  ruptured  by  shrinking  on  these  cores.  Thus, 


TREATMENT   OF   CASTINGS   WHILE   COOLING  179 

jacketed  cylinders  having  light  jacket  walls  and  heavy  barrels 
must  have  the  cores  removed  promptly  to  prevent  the  barrel 
cracking  away  from  the  jacket.  Cored  cylinders  frequently 
have  internal  strains  set  up  in  them  by  shrinking  on  the  cores, 
and  when  the  first  roughing  cut  is  made  on  them  in  the  ma- 
chine-shop these  strains  are  relieved  and  warp  the  casting, 
which  as  a  result  must  be  annealed. 

In  situations  where  a  circle  of  iron  of  one  thickness  has 
another  circle  of  greater  thickness  cast  inside  it,  there  is  con- 
siderable danger  of  cracking  owing  to  the  thicker  circle  cooling 
last  and  pulling  away  from  the  lighter  outside  one.  To  offset 
this  tendency  considerable  ingenuity  is  sometimes  required. 
Usually  there  is  one  particular  spot  in  castings  of  this  character 
which  always  gives  trouble  and,  in  a  certain  case,  this  was 
obviated  by  placing  a  chill  at  a  particularly  heavy  part  and 
chilling  the  iron  as  it  was  poured  so  that  it  cooled  relatively 
faster  than  at  the  other  portions  of  the  casting. 

In  loam  molds,  provision  for  shrinkage  is  made  by  inserting 
in  the  mold  loam  bricks  which  crush  under  the  contraction  of 
the  metal,  and  also  by  the  insertion  of  iron  plates  in  the  mold 
which  can  be  pulled  out  as  soon  as  the  casting  is  poured  and 
thus  provide  ample  space  in  which  the  metal  may  shrink. 
The  larger  the  casting  and  the  faster  the  cooling,  the  greater 
is  the  relative  contraction,  and  this  must  be  borne  in  mind 
when  making  the  mold,  in  order  that  proper  provision  may  be 
made  for  taking  care  of  this  contraction. 

After  the  casting  has  been  removed  from  the  sand,  care 
must  be  exercised  in  its  treatment  until  it  has  cooled  down  to 
room  temperature.  A  large  casting  which  may  be  exposed  to  a 
chilling  draft  on  one  side,  such  as  might  come  from  a  door 
communicating  with  outdoors  in  the  winter  time,  would  cool 
more  rapidly  on  that  side  than  on  the  other  and  thus  crack 
just  as  surely  as  it  would  in  the  mold  had  no  provision  been 
made  for  crushing  the  cores.  Printing-press  cylinders  exposed 
to  unequal  temperatures  on  opposite  sides  are  especially  liable 
to  warping. 

The  composition  of  the  iron  of  which  the  casting  is  com- 


I8O  FOUNDRY   PRACTICE 

posed  also  has  an  influence  on  its  treatment  after  pouring. 
Light  castings  of  machine  parts  are  usually  removed  from  the 
sand  immediately  after  the  mold  is  poured.  These  castings 
are  high  in  silicon  and  lowin  sulphur,  manganese,  and  combined 
carbon.  A  coating  of  sand  frequently  adheres  to  such  castings 
in  proportion  to  the  thickness,  protecting  them  from  the  air. 
However,  if  air  does  come  in  contact  with  the  casting,  the 
high  silicon  and  the  high  graphitic  carbon  content  prevent  the 
formation  of  a  hard  scale.  On  the  other  hand,  if  the  sulphur 
and  manganese  contents  are  high  the  reverse  will  be  true  and 
a  hard  scale  will  form  on  the  castings  if  the  air  is  permitted  to 
strike  them  before  they  have  cooled  to  room  temperature.  It 
is  therefore  advisable  to  leave  them  in  the  sand  until  they  are 
cold,  especially  if  they  are  to  be  machined  later.  Should  it  be 
necessary  for  any  reason  whatever  to  remove  them  from  the 
sand  promptly  they  should  be  poured  with  iron  of  a  silicon 
content  about  twenty  points  higher  than  ordinarily. 

The  thinner  the  wall  of  the  casting  to  be  machined  the 
greater  is  the  danger  of  removing  it  from  the  sand  too  quickly 
and  of  forming  on  the  surface  of  it  a  hard  scale.  When  un- 
covering such  castings,  to  equalize  the  cooling,  a  small  amount 
of  sand  should  be  allowed  to  remain  on  surfaces  which  are  to 
be  machined.  This  will  prevent  direct  contact  with  the  air 
and  thus  avoid  scale  and  yet  will  permit  the  rapid  escape  of 
heat. 

Castings  which  are  found  to  be  crooked  on  removal  from 
the  sand  may  be  straightened  by  heating  them  to  a  red  heat 
and  then  weighting  them  so  that  the  casting  will  be  bent  in 
the  opposite  direction.  Lathe  beds  and  similar  castings  may 
be  treated  in  this  manner,  the  ends  being  placed  on  solid  bear- 
ings, the  casting  arching  upward  and  being  heated  at  the 
center  until  it  is  red  hot,  after  which  it  is  weighted  and  allowed 
to  cool.  Many  times  castings  may  be  straightened  by  peen- 
ing  on  the  hollow  side,  thus  closing  the  grain  of  the  iron  and 
forcing  the  ends  down. 


CHAPTER  XVIII 

CLEANING  CASTINGS 

FOR  cleaning  castings  from  the  sand  which  adheres  to  them 
after  pouring,  three  general  methods  are  in  use :  rattling  them 
in  a  tumbling  barrel,  pickling,  and  sand  blasting.  In  rattling, 
the  castings  are  placed  together  in  a  horizontal  barrel  which 
is  revolved  and  the  castings  fall  over  and  over  and  against  one 
another,  and  the  sand  and  scale  are  gradually  pounded  from 
the  surface.  This  method,  however,  produces  a  hard  skin  on 
the  surface  of  the  casting  which  renders  it  more  difficult  to 
machine,  and  pickling  in  sulphuric,  muriatic,  or  hydrofluoric 
acid  is  more  generally  resorted  to  for  castings  which  are  later 
to  be  subjected  to  machine  processes.  Sand  blasting  consists 
in  directing  against  the  casting,  by  means  of  air  under  a  pres- 
sure of  from  sixty  to  one  hundred  pounds  per  square  inch,  a 
jet  of  sharp  sand  which  abrades  not  only  the  burned  sand  but 
also  the  hard  surface  of  the  casting. 

In  rattling,  the  castings  are  placed  in  the  barrel  until  it  is 
nearly  full,  together  with  "stars"  or  "picks,"  which  are  small, 
irregularly  shaped  pieces  of  hard  iron,  and  the  barrel  closed 
and  revolved.  The  castings  falling  on  each  other  and  on  the 
"stars"  knock  from  the  surface  all  the  burned  sand  and  scale 
and  polish  each  other.  In  rattling  together  such  castings  as 
legs  for  machines  it  is  advisable  to  pack  the  castings  in  with 
blocks  of  wood  to  hold  them  apart  and  allow  the  "stars"  to 
do  the  abrading  and  polishing  when  the  barrel  is  revolved. 
Heavy  castings  of  this  character  are  liable  to  become  broken 
if  placed  in  the  barrel  loose.  If  the  barrel  is  not  well  filled  with 
castings  it  is  advisable  to  fill  the  remainder  of  the  space  with 
blocks  of  wood  if  the  castings  are  of  light  character. 

For  many  purposes  rattling  is  insufficient  to  clean  the 
casting  properly.  If  a  casting  has  been  made  in  raw  sand  with- 
181 


1 82  FOUNDRY    PRACTICE 

out  any  facing,  the  sand  will  apparently  be  burned  on  it. 
Rattling  will  not  remove  this  burned  sand  properly  and  pickling 
is  necessary.  The  pickling  bath  is  placed  in  a  stone  or  wooden 
trough  and  may  consist  of  sulphuric  acid  diluted  in  the  propor- 
tions of  one  part  acid  to  seven  parts  water,  or  of  muriatic  acid 
and  water,  or  one  part  of  hydrofluoric  acid  to  twenty  parts  of 
water.  The  castings  should  remain  in  the  pickling  bath 
about  twelve  hours  and  then  should  be  well  washed  with  clear 
water.  As  much  of  the  sand  as  possible  should  be  removed 
from  them  before  placing  them  in  the  bath.  Gears  are  cleaned 
best  by  first  subjecting  them  to  a  sand  blast,  which  loosens  the 
sand  in  the  corners  of  the  teeth,  and  then  pickling  them. 

The  following  information  concerning  the  use  of  hydro- 
fluoric acid  is  given  in  a  pamphlet  issued  by  the  General 
Chemical  Company.  "Until  quite  recently  castings  have  been 
cleaned  either  by  mechanical  means  or  by  dilute  sulphuric 
acid.  Sulphuric  acid  loosens  the  sand  by  dissolving  the  iron 
from  under  it.  On  the  other  hand  hydrofluoric  acid  dissolves 
the  sand  itself,  and  therefore  acts  morfe  promptly,  takes  much 
less  acid,  and  does  not  cause  a  loss  of  iron.  For  cleaning  cast- 
ings that  are  to  be  galvanized,  tinned,  enameled,  nickel-plated, 
or  painted,  hydrofluoric  acid  is  vastly  superior  to  sulphuric  or 
muriatic  acid  because  it  leaves  a  purer  metallic  surface  and 
does  not  rust  the  plating  or  work  through  the  paint.  Hydro- 
fluoric acid  dissolves  more  readily  than  sulphuric  or  muriatic 
acid,  the  ordinary  rust  and  magnetic  (black)  oxide  that  forms 
on  the  surface  of  heated  iron.  The  strength  at  which  the  acid 
is  used  varies  with  the  kind  of  iron  to  be  cleaned  and  the  time 
in  which  it  is  to  be  finished,  but  generally  it  is  used  in  the 
proportions  of  one  gallon  of  acid  to  twenty  or  twenty-five 
gallons  of  water.  The  acid  should  be  poured  into  the  water 
and  well  stirred.  Such  a  solution  will  clean  ordinary  castings 
in  from  one-half  hour  to  one  hour.  If  used  of  half  this  strength 
— one  gallon  of  acid  to  fifty  gallons  of  water — it  will  take 
several  hours.  Hydrofluoric  acid  is  used  cold,  but  should  be 
kept  above  the  freezing  point.  The  bath  can  be  used  re- 
peatedly by  adding  about  one-third  the  original  quantity  of 


CLEANING   CASTINGS  183 

acid  before  charging  again  with  iron.  If  it  is  desired  to  keep 
the  iron  bright  it  should  be  washed  with  water  at  about 
200°  Fahr.  immediately  after  coming  out  of  the  acid  so  as 
to  dry  quickly.  By  this  means  all  trace  of  the  acid  is  eradi- 
cated and  all  chance  of  corrosion  or  tarnish  resulting  is  ob- 
viated. If  washed  with  cold  water  the  casting  will  remain 
wet  for  some  time  and  rust.  A  little  lime  may  be  added  to 
the  wash  water.  For  immersing  and  removing  castings  from 
the  bath,  wooden  boxes  with  holes  in  the  sides  have  been  used 
with  good  results.  By  this  means  the  sand  is  retained  at 
the  bottom  of  the  boxes  and  is  removed  with  the  castings,  thus 
saving  the  strength  of  the  acid  when  not  in  use.  Spent,  weak 
acids  should  be  discarded  and  the  tanks  cleaned  every  month. 
In  removing  stoppers  from  vessels  containing  the  acid,  care 
should  be  exercised,  as  sometimes  gas  is  generated  from  the 
action  of  the  acid  on  the  lead  in  which  it  is  enclosed  which 
may  cause  some  of  the  acid  to  be  thrown  out  if  the  corks  are  re- 
moved hastily.  The  acid  is  neither  explosive  nor  inflammable. 
As  strong  acid  will  cause  inflammation  wherever  it  comes  in 
contact  with  the  skin  it  should  be  handled  as  carefully  as  other 
acids.  Rubber  gloves  are  the  best  protection,  but  if  acid  has 
splashed  on  the  skin  it  should  be  washed  off  with  water  and 
diluted  borax  or  sal  soda  solution,  or  with  aqua  ammonia 
which  will  prevent  injury," 


CHAPTER   XIX 

MOLDING  MACHINES 

WHERE  there  are  a  number  of  molds  to  be  made  from  one 
pattern,  it  is  frequently  advisable  to  use  a  molding  machine 
for  this  purpose.  Molding  machines  are  made  in  a  number 
of  varieties,  each  designed  for  some  specific  purpose.  Thus  we 
have  the  power  squeezer  and  the  hand  squeezer,  the  split-pattern 
squeezer,  the  jarring  machine,  also  known  as  a  jolt  rammer,  and 
the  roll-over  machines,  which  are  made  to  operate  entirely  by 
hand,  or  to  use  power  for  rolling  over  and  drawing  the  pattern, 
the  ramming  being  done  by  hand,  or  to  use  power  both  for 
ramming  and  for  rolling  over  and  pattern  drawing.  Each 
machine  has  its  particular  field  in  which  it  will  do  better  work 
than  one  of  the  other  types. 

Where  the  ramming  time  is  a  large  factor  in  the  time 
required  to  make  the  mold,  one  of  the  squeezer  machines  or 
jarring  machines  is  advisable.  However,  if  the  mold  is  such 
that  the  finishing  time  is  the  largest  factor,  a  machine  which 
will  draw  the  pattern  should  be  adopted.  This  brings  us  to 
the  split-pattern  machine  which,  however,  is  limited  in  its 
application  to  patterns  which  can  be  split  on  a  true  plane 
and  molded  one-half  in  the  cope  and  the  other  half  in  the  drag, 
or  to  one  of  the  roll-over  machines  operated  either  by  hand 
or  by  power.  In  selecting  the  machine  to  save  ramming  time 
the  character  of  the  mold  to  be  made  is  the  chief  considera- 
tion. As  the  squeezer  machine  packs  the  sand  to  the  density 
required  for  the  mold  by  pressure  applied  at  the  outside  sur- 
face of  the  mold,  it  is  not  well  adapted  to  molds  having  deep 
bodies  of  sand,  since  in  this  case  the  sand  will  have  the  greatest 
density  at  the  outer  surface  instead  of  against  the  pattern  as  is 
required.  On  the  other  hand,  the  jarring  machine  in  which 
the  sand  itself  forms  the  ramming  medium  is  well  adapted  to 
molds  in  which  there  are  large  pockets  of  hanging  sand. 
184 


MOLDING   MACHINES  185 

Having  thus  considered  the  general  properties  of  molding 
machines,  we  will  now  consider  each  type  in  detail.  First  in 
the  list  is  the  hand  squeezer.  This  consists  simply  of  a  frame 
carrying  a  yoke,  a  plate  on  which  the  mold-board  is  set  and 
which  can  be  elevated  toward  the  yoke  by  means  of  a  hand 
lever  operated  by  the  molder.  The  flask  is  placed  on  the 
mold-board  with  the  pattern  in  it  in  the  proper  position  and 
sand  is  riddled  over  the  pattern  until  it  is  covered.  Sand 
from  the  heap  is  then  shoveled  in  and  struck  off  flush  with  the 
top  of  the  flask,  a  bottom-board  fitting  within  the  flask  is 
placed  on  top  of  the  mold  and  the  whole  contrivance  elevated 
against  the  yoke  by  means  of  the  hand  lever.  This  operation 
compresses  the  sand  in  the  flask  to  the  required  density  and 
the  mold  is  then  lowered  to  the  original  position,  turned  over, 
and  the  pattern  drawn.  It  may  be  drawn  either  in  the  usual 
manner  by  means  of  a  draw-nail  which  is  rapped  by  the 
molder,  or  the  pattern  may  be  mounted  in  a  vibrator  frame  as 
described  later  and  vibrated  by  means  of  compressed  air 
while  it  is  being  drawn.  This  latter  method  gives  much  the 
better  molds. 

Power  Squeezers. — Of  much  greater  capacity  and  scope 
is  the  power  squeezing  machine  shown  in  Fig.  130.  This  is 
a  machine  designed  especially  for  molding  light  snap-flask 
work.  It  consists  of  a  yoke  carried  between  two  uprights, 
the  yoke  being  adjustable  to  suit  varying  depths  of  flasks; 
a  power  cylinder  for  elevating  the  table  of  the  machine  on 
which  the  mold-board  and  the  flask  are  mounted;  a  lever  for 
controlling  the  admission  of  air  to  the  power  cylinder,  and  a 
connection  for  operating  the  vibrator  by  compressed  air. 
The  yoke  in  the  type  of  machine  illustrated  is  mounted  on 
trunnions  enabling  it  to  be  swung  back  out  of  the  way  for 
placing  and  removing  the  flasks  and  the  molds  on  the  table. 
The  patterns  are  usually  mounted  in  vibrator  frames  or  on 
match-plates  to  render  the  operation  of  drawing  them  easy 
and  accurate.  Machines  of  this  character  require  about  four 
cubic  feet  of  free  air  per  minute  for  their,  operation. 

The  operation  of  making  the  mold  on  this  machine  with 


1 86  FOUNDRY    PRACTICE 

the  patterns  mounted  on  a  vibrator  frame  is  as  follows:  A  hard- 
sand  match  is  formed,  on  which  patterns  mounted  in  a  vibrator 
frame  are  set.  This  match  is  placed  on  the  table  of  the 
machine  and  the  drag  portion  of  the  flask  set  in  position  and 
sand  riddled  over  the  pattern  until  the  latter  is  covered. 
Sand  is  then  shoveled  in  until  the  flask  is  filled,  the  excess 
sand  being  struck  off  with  the  bottom-board,  which  is  next 
placed  over  the  flask  and  the  yoke  of  the  machine  is  drawn 
forward  to  its  vertical  position.  Air  is  then  admitted  to  the 
power  cylinder  and  the  table  elevated,  thus  squeezing  the 
sand  in  the  flask  against  the  yoke.  The  air  is  exhausted  from 
the  cylinder  and  the  mold  lowered  to  its  original  position, 
the  half-flask  pattern  and  hard-sand  match  then  being  rolled 
over.  The  match  is  next  removed,  after  which  parting  sand 
is  shaken  on  the  mold  and  the  cope  half  of  the  flask  put  in 
place,  filled  with  sand,  and  squeezed  in  the  same  manner  as 
the  drag.  This  completes  the  ramming  operations  and  the 
sprue  is  cut  with  a  brass  tube  used  as  a  sprue  cutter. 

The  vibrator  is  now  started  and  the  molder  grasping  the 
cope  by  its  handles  lifts  it  from  the  drag.  The  snap  flasks 
used  with  these  machines  have  accurately  fitted  pins  of  con- 
siderable length  which  act  as  guides  when  the  pattern  is  drawn, 
the  vibrator  frames  or  match-plates  having  ears  which  fit 
closely  to  these  pins,  thus  being  guided  vertically  upward 
from  the  mold.  After  the  cope  has  been  lifted  off  and  set  aside, 
the  vibrator  is  once  more  started  and  the  pattern  is  drawn  by 
lifting  the  vibrator  frame  in  its  guides.  The  pattern  being 
drawn,  the  mold  may  be  closed,  the  snap  flask  removed,  and 
the  mold  set  on  the  floor  ready  for  pouring. 

To  make  hard-sand  match  to  use  with  the  vibrator  frame, 
the  latter  is  put  in  the  cope  flask  and  rammed  up.  The  part- 
ing is  made  in  green  sand  and  lycopodium  is  dusted  on  the 
parting  between  the  green  sand  and  the  preparation  forming 
the  match.  The  match  frame  which  is  beveled  to  hold  the 
match  in  place  is  set  over  the  pattern  and  clamped  firmly  so 
that  it  cannot  move  during  the  ramming  operation.  The 
portion  of  the  pattern  projecting  into  the  frame  is  rammed 


MOLDING    MACHINES 


FIG.  130. — POWER  SQUEEZER  MOLDING  MACHINE. 


1 88  FOUNDRY    PRACTICE 

up  exactly  as  would  be  done  for  bench  molding,  with  sand 
made  up  of  fifteen  pounds  of  new  burnt  molding  sand,  riddled 
through  a  No.  30  sieve,  into  which  has  been  kneaded  a  mix- 
ture of  one  quart  of  boiled  linseed  oil  and  four  ounces  of 
litharge.  The  match  and  the  green-sand  half-mold  are  rolled 
over  and  the  cope  taken  off.  The  pattern  is  drawn  and  any 
parts  of  the  match  which  may  have  broken  in  drawing  are 
mended,  after  which  the  match  is  dried  in  a  warm  place  for 
about  twelve  hours  when  it  may  be  coated  with  thin  shellac. 

Instead  of  using  a  hard-sand  match,  aluminum  match-plates, 
with  the  patterns  cast  one-half  on  either  side  of  the  plate, 
may  be  used,  especially  if  the  patterns  have  an  irregular  part- 
ing and  exceptionally  good  castings  are  required.  The  ad- 
vantage of  these  aluminum  match-plates  is  that  the  whole  mold 
may  be  squeezed  at  one  operation  and,  furthermore,  there  is 
no  possibility  of  the  cope  and  drag  shifting  in  relation  to  one 
another.  To  make  an  aluminum  match-plate,  a  mold  of  the 
patterns  is  made  in  a  flask  large  enough  to  accommodate  the 
size  of  plate  necessary.  Master  patterns  should  be  used  which 
have  been  made  with  the  proper  allowance  for  shrinkage  and 
finish.  Great  care  should  be  taken  in  making  this  mold  in 
order  to  avoid  any  unnecessary  finishing  in  the  plate.  Strips 
of  wood  the  thickness  of  the  plate  required  are  placed  on  the 
parting  of  the  drag  before  the  mold  is  closed  and  a  false  part- 
ing of  sand  built  up  to  the  level  of  these  strips.  The  strips 
are  then  removed,  the  mold  is  closed  and  poured,  after  which 
the  plate  may  be  finished  with  a  wire  brush  or  scraper.  After 
attaching  suitable  handles  and  guides  to  the  ends,  the  plate  is 
ready  for  use. 

To  make  a  mold  by  means  of  this  plate,  the  flask  is  put 
together  on  the  table  of  the  machine  with  the  plate  between 
the  two  halves,  the  drag  side  being  uppermost.  Parting 
sand  is  dusted  on  the  plate  and  the  drag  filled  with  sand,  the 
first  portion  being  riddled  in  until  the  patterns  are  covered. 
The  bottom-board,  being  used  first  to  strike  off  excess  sand,  is 
placed  in  position,  after  which  the  flask  is  rolled  over,  the  cope 
filled  with  sand,  and  the  mold  squeezed.  The  cope  is  then 


MOLDING    MACHINES  189 

lifted  off,  the  vibrator  being  used,  after  which  the  pattern 
plate  is  also  lifted.  The  sprues  having  been  cut  before  lifting 
the  cope,  the  mold  may  now  be  closed  ready  for  pouring. 

Instead  of  the  two  methods  above  described,  paraffine 
boards  may  be  used  for  mounting  the  pattern  where  there  are 
not  a  great  number  of  molds  to  be  made  from  one  set  of  pat- 
terns. They  are  especially  desirable  in  flat-back  work  or  for 
split-pattern  work.  The  paraffine  board  is  usually  made  of 
oak  and  is  boiled  in  paraffine  for  forty-eight  hours  to  prevent 
it  warping  in  contact  with  damp  sand.  It  is  mounted  in  a 
vibrator  frame  and  the  patterns  fastened  to  it  by  means  of 
wood  screws,  having  first  been  located  in  position  by  means  of 
dowel  pins.  Where  castings  are  to  be  made  from  split-pat- 
terns in  large  quantities,  a  three-sixteenths  inch  steel  plate 
may  be  used.  The  patterns  are  mounted  one-half  on  each 
side  of  the  plate  and  the  entire  mold  is  squeezed  at  one  time 
as  is  the  case  with  aluminum  match-plates.  In  mounting  the 
patterns,  the  corresponding  halves  should  be  finished  together 
so  that  they  will  match  at  the  parting.  A  hole  should  be 
drilled  and  slightly  countersunk  before  the  two  halves  are 
separated.  After  separation,  one  half  should  be  laid  in  the 
desired  position  on  the  steel  plate  and  used  as  a  jig  in  drilling 
the  latter.  After  the  drilling  is  completed  the  corresponding 
half-patterns  should  be  placed  on  the  opposite  side  of  the  plate 
and  the  two  parts  riveted  to  the  plate  by  means  of  a  brass  rod 
inserted  through  the  drilled  holes  and  riveted  into  the  counter- 
sink. 

The  illustration,  Fig.  131,  shows  the  method  of  suspending 
patterns  in  a  vibrator  frame.  A  carrier  of  sheet  brass  one- 
eighth  inch  in  thickness  is  soldered  or  sweated  to  the  pattern, 
being  attached  to  the  runners  if  possible.  Carriers  are  then 
rigidly  fastened  to  the  vibrator  frame  by  first  inserting  them  in 
a  slot  in  the  frame  and  drilling  two  three-sixteenths-inch  holes 
through  both  frame  and  carrier  and  fastening  them  together 
by  means  of  a  snugly  fitting  brass  pin.  The  pattern  is  next 
placed  in  the  vibrator  frame  and  holes  drilled  in  the  carriers 
on  the  pattern.  The  carriers  on  the  pattern  and  those  in  the 


190  FOUNDRY    PRACTICE 

frame  come  together,  and  the  carriers  in  the  frame  are  drilled 
to  correspond  with  holes  already  drilled  in  the  carriers  on  the 
pattern.  The  slot  in  the  vibrator  frame  should  then  be  filled 
with  wax  to  prevent  the  mold  from  crumbling  at  the  edges. 

The  vibrator  is  simply  a  small  compressed-air  hammer 
striking  a  large  number  of  blows  of  uniform  intensity  per 
minute,  the  head  of  this  hammer  being  attached  to  the  vibrator 
frame  or  match-plate  to  communicate  the  blows  of  the  hammer 
to  the  pattern.  The  blows  are  such  that  the  size  of  the  mold 
is  not  enlarged  to  any  extent,  but  they  simply  overcome  the 
friction  of  the  pattern  against  the  sand,  and  enable  the  drawing 
of  a  pattern  which  has  no  draft. 

Split-Pattern  Machines. — Fig.  132  illustrates  a  special 
type  of  molding  machine  adapted  for  split- pattern  work.  It 
is  especially  adapted  to  patterns  which  are  symmetrical,  in 
which  case  both  cope  and  drag  may  be  molded  from  one 
pattern  plate  containing  a  double  set  of  half-patterns,  those 
on  one  side  of  the  mold  in  the  cope  matching  those  on  the 
opposite  side  in  the  drag.  In  using  this  machine  it  is  cus- 
tomary to  make  as  many  drag  portions  of  the  molds  as  may  be 
required,  placing  them  on  the  floor  in  position  for  pouring,  after 
which  the  copes  are  formed  and  closed  on  the  drags.  If  cores 
are  required  in  the  mold,  they  are,  of  course,  set  before  the 
copes  are  made.  It  will  be  observed  that  the  machine  is 
similar  in  appearance  to  the  power  squeezer  described  above. 
It  is,  however,  provided  with  an  arrangement  for  drawing  the 
pattern  either  by  hand  or  power  and  also  either  by  raising 
the  mold  away  from  the  pattern  or  by  drawing  the  latter  down 
through  a  stripping  plate. 

To  make  a  mold  on  this  machine,  the  patterns,  which  are 
mounted  on  a  steel  plate,  are  set  on  the  table  of  the  machine, 
the  flask  placed  around  them,  being  accurately  located  by 
means  of  dowel  pins  on  the  machine,  and  it  is  filled  with  sand 
and  squeezed  in  the  usual  manner.  After  squeezing,  the  mold 
is  lowered  to  its  original  position  and  the  vibrator  started. 
The  operator  then  presses  down  on  a  pattern-drawing  lever, 
if  a  hand-draft  machine,  or  admits  air  to  the  drawing  cylinder, 


MOLDING   MACHINES 


FIG.  131. — I,  Mounting  Patterns  in  a  Vibrator  Frame;  2,  Hard-Sand 
Match  for  Same  Patterns;  3,  Cope  of  Mold  Made  from  these  Patterns; 
4,  Drag  of  Mold. 


I Q2  FOUNDRY    PRACTICE 

if  a  power-drawing  machine,  which  elevates  the  outer  portion 
of  the  table  on  which  the  flask  is  carried  clear  of  the  patterns, 
when  the  half-mold  may  be  removed  from  the  machine  and  set 
on  the  floor.  The  operation  of  making  copes  and  drags  on 
this  machine  is  similar,  except  that  in  the  case  of  copes 
the  location  of  the  sprue  is  indicated  by  a  button  on  the 
bottom  board  which' marks  a  depression  in  the  sand  where  the 
gate  is  to  be  cut  by  means  of  the  sprue  cutter.  When  used 
with  a  stripping ''  plate,  the  patterns  are  drawn  downward 
through  the  stripping  plate,  the  mold  remaining  stationary. 

The  illustration,  Fig.  133,  shows  the  method  of  stooling 
patterns  molded  on  this  type  of  machine  where  there  are  large 
bodies  of  hanging  sand  which  would  be  liable  to  drop  when  the 
pattern  is  drawn.  Such  bodies  are  those  forming  the  green- 
sand  cores  of  the  stuffing  boxes  in  the  illustration.  A  hole  is 
cut  in  the  pattern  plate  the  exact  size  of  the  green-sand  core 
or  through  the  pattern  and  pattern  plate  according  to  the 
requirements  of  the  case.  A  stool,  made  usually  of  cold-rolled 
steel  and  of  the  exact  size  of  the  core,  is  attached  to  a  stool 
plate  underneath  and  in  exact  alignment  with  the  holes  in  the 
pattern  plate.  When  the  mold  is  elevated  to  draw  the  pattern 
the  steel  plate  rises  with  the  tables  of  the  machine  and  the 
stools  support  the  hanging  green-sand  cores  as  shown  until 
they  are  entirely  clear  of  the  pattern. 

The  mounting  of  the  two  halves  of  a  symmetrical  pattern 
for  use  in  a  split-pattern  machine  is  a  job  requiring  considerable 
care  and  great  accuracy.  The  recommended  method  is  the 
use  of  a  transfer  plate.  The  first  operation  is  to  make  a 
pattern  plate  for  the  machine  and  drill  in  it  two  dowel  holes 
located  on  the  center  line  of  the  plate.  The  halves  of  the 
various  patterns  are  doweled  together  before  finishing,  after 
which  they  are  numbered  and  separated.  The  halves  without 
dowel  pins  are  arranged  on  one  side  of  the  pattern  plate  and 
used  as  jigs  to  drill  that  side  of  the  plate.  A  transfer  plate 
somewhat  wider  than  half  the  width  of  the  pattern  plate  is 
next  made  by  first  drilling  holes  to  match  the  center-line  holes 
of  the  pattern  plate.  Transfer  and  pattern  plates  are  now 


MOLDING    MACHINES 


193 


FIG.  132. — SPLIT-PATTERN  MOLDING  MACHINE. 


194 


FOUNDRY    PRACTICE 


fastened  together,  being  located  with  reference  to  each  other 
by  means  of  dowel  pins  in  the  center-line  holes.  Using  the 
pattern  plate  as  a  jig,  holes  are  drilled  in  the  transfer  plate 
to  correspond  with  those  drilled  in  the  pattern  plate,  after 
which  the  transfer  plate  is  turned  over,  not  around,  so  that 
what  was  its  upper  surface  is  now  its  lower  one  and  it  is  once 


FIG.  133. — STOOLING  PATTERNS  ON  A  SPLIT-PATTERN  MACHINE. 


more  placed  on  the  pattern  plate,  the  dowels  inserted  in  the 
center-line  holes,  and  it  is  used  as  a  jig  to  drill  the  holes  in  the 
undrilled  side  of  the  pattern  plate.  The  two  sets  of  holes  in 
the  pattern  plate  will  thus  be  symmetrical  around  the  center 
line,  and  when  the  half-patterns  are  doweled  to  this  plate 
molds  made  from  them  will  match  perfectly. 

Jarring  Machines. — For  large  deep  work  in  which  the 
ramming  time  is  of  considerable  importance,  or  for  large  cores, 
the  jarring  machine  is  of  especial  importance.  This  machine 


MOLDING   MACHINES  IQ5 

requires  heavy  flasks  and  large  quantities  of  sand.  It  consists 
essentially  of  a  table  of  massive  construction  which  may  be 
elevated  any  desired  distance  by  means  of  air  pressure  and 
then  suddenly  dropped.  The  pattern,  flask  and  sand  are 
carried  on  this  table,  which  when  it  is  dropped  falls  more 
rapidly  than  do  the  former.  The  inertia  of  the  sand  and 
flask  striking  the  table  after  the  latter  has  come  to  rest  causes 
the  sand  to  be  firmly  packed  in  the  mold.  The  density  to 
which  the  sand  can  be  packed  varies  with  the  length  of  drop 
and  the  efficiency  of  the  machine  increases  with  the  drop  and 
decreases  with  the  dead  weight  handled  over  and  above  the 
weight  of  the  sand.  The  machine,  to  secure  best  results,  must 
be  solidly  constructed  in  the  table,  and  in  operation  there  must 
be  no  movement  between  the  pattern,  sand,  and  flask  which 
will  tend  to  pull  the  sand  apart  or  to  fracture  the  sand  into 
various  layers.  Badly  fitted  pattern  boards  or  patterns  which 
are  too  light  for  their  work,  flasks  which  are  crooked,  or  a  light 
table  on  the  machine  will  tend  to  cause  such  fractures.  In 
ramming  a  mold  on  this  type  of  machine  it  is  only  necessary 
to  place  the  pattern  in  position,  set  the  flask  around  it,  riddle 
sand  over  the  pattern,  and  open  the  air  valve.  After  the 
table  has  been  given  a  sufficient  number  of  strokes  to  ram  the 
sand  to  the  proper  density,  the  mold  may  be  removed  and 
finished  by  any  of  the  approved  methods. 

The  latest  development  in  connection  with  the  jarring 
machine  is  the  shockless  jarring-machine,  a  cross  section  of 
which  is  shown  in  Fig.  134.  This  is  a  machine  in  which  the 
impact  of  the  mold  on  the  table  is  absorbed  within  the  machine 
itself  instead  of  being  transmitted  to  the  foundation  and  thence 
to  the  surrounding  floors  and  buildings.  One  great  disad- 
vantage of  the  plain  jarring  machine  is,  that  in  ramming  large 
molds,  involving  heavy  masses  of  sand,  vibrations  are  set  up 
for  a  considerable  distance  around  the  machine  and  these 
vibrations  are  not  only  disagreeable  to  the  workers  but  may 
also  shake  down  the  sand  in  completed  molds,  thus  doing  con- 
siderable damage.  These  vibrations  in  the  case  of  the  machine 
under  consideration  are  eliminated  by  means  oi  an  anvil 


196 


FOUNDRY    PRACTICE 


mounted  in  a  cylinder  and  supported  on  long  helical  steel 
springs.  The  table  is  elevated  by  compressed  air  admitted 
to  the  jarring  cylinder  to  raise  the  table.  At  a  predetermined 
point  in  the  table  movement,  the  air  is  automatically  cut  off, 
and  expanding,  raises  the  table  still  further.  The  air  from  the 
jarring  cylinder  exhausts  into  the  anvil  cylinder  and  the  jarring 
table  falls  by  gravity.  At  the  same  time,  the  anvil  being  re- 


FIG.  134. — SHOCKLESS  JARRING  MACHINE  SET  UP  IN  PIT. 

lieved  of  a  considerable  portion  of  its  load,  is  thrown  upward 
by  its  supporting  springs  to  meet  the  falling  table.  The 
velocity  with  which  it  rises  is  increased  by  the  air  expanded 
from  the  jarring  cylinder  into  the  anvil  cylinder.  The  anvil 
and  the  table  are  brought  to  rest  by  their  impact  upon  each 
other,  giving  great  ramming  effect  upon  the  sand  but  without 
giving  vibration  to  the  surrounding  floors,  the  vibrations  being 
absorbed  by  the  springs  and  air  under  the  anvil.  Machines 


MOLDING     MACHINES  197 

of  this  character  are  built  to  ram  molds  weighing  as  much 
as  50,000- pounds. 

Roll-over  Machines. — A  roll-over  machine  in  which  the 
pattern,  flask,  and  mold  are  rolled  over  and  the  pattern  drawn 
by  hand  is  shown  in  Fig.  135.  The  great  advantage  of  the 
roll-over  machine  is  that  it  is  portable  and  follows  up  the  sand 
pile  as  it  is  consumed,  leaving  behind  it  completed  molds  as  is 


FIG.  135. — PLAIN  HAND  ROLL-OVER  MACHINE. 

done  in  hand  molding.  It  is  especially  valuable  for  making 
intricate  molds  from  straight  patterns  with  little  or  no  draft, 
and  avoids  entirely  any  patching  or  finishing  of  molds.  A 
typical  pattern  molded  on  a  roll-over  machine  is  a  grate-bar 
pattern  forming  about  one  hundred  and  fifty  deep  green-sand 
cores.  This  would  be  a  most  difficult  mold  to  make  and  draw 
by  hand  and  the  time  required  for  finishing  would  be  no  small 
item.  However,  with  the  roll-over  machine,  patching  and  fin- 
ishing of  the  mold  is  the  exception  and  the  output  of  such  a  ma- 
chine on  work  of  this  character  far  exceeds  that  of  hand  molding. 
The  machine  consists  essentially  of  a  frame  on  which  the 
mold-board  with  the  patterns  is  attached.  This  frame  is 
carried  on  trunnions,  which  in  turn  are  supported  on  sliding 


198  FOUNDRY    PRACTICE 

frames  mounted  on  accurately  machined  guides.  The  frame 
can  be  revolved  about  these  trunnions  through  a  half-circle  in 
order  to  roll  the  mold  over  and  bring  it  in  position  for  drawing 
the  pattern.  This  latter  operation  is  accomplished  by  means 
of  a  lifting  lever  which  raises  the  frame  with  the  mold-board 
and  pattern  attached  vertically  upward,  it  being  guided  by 
the  sliding  frames  working  on  the  guides  before  mentioned, 
thus  enabling  parallel  patterns  to  be  drawn  without  the  aid 
of  draft.  Should  by  any  chance  any  portion  of  the  mold 
become  broken  in  drawing  the  pattern,  the  guides  enable  the 
patterns  to  be  replaced  in  the  mold  with  exactness,  after  which 
the  mold  can  be  mended  much  more  quickly  and  satisfactorily 
than  otherwise. 

In  molding  with  this  machine,  the  pattern  board  is  placed 
on  the  hinged  frame  and  clamped  to  it.  The  flask  is  then 
placed  on  the  pattern  board,  its  location  being  determined  by 
pins  on  the  latter.  The  flask  is  then  filled  and  rammed  as 
in  floor  or  bench  molding  and  the  mold  struck  off.  The  bottom- 
board  is  then  next  rubbed  on  the  mold  and  clamped  to  the 
pattern  board.  The  hinged  frame  is  then  rolled  over  until  the 
bottom-board  rests  on  the  equalizing  cradle.  The  pattern- 
drawing  lever  is  next  drawn  down  until  the  stops  on  the 
hinged  frame  engage  the  stops  on  the  frame  of  the  machine 
and  the  flask  is  allowed  to  settle  by  gravity  on  the  cradle. 
The  clamps  are  then  released  and  the  vibrator  started,  after 
which  the  pattern  is  drawn  by  lifting  the  pattern  board  clear  of 
the  mold  by  means  of  a  pattern-drawing  lever,  the  frame  and 
pattern  board  being  guided  vertically  upward  by  means  of  a 
guide  on  the  machine.  As  soon  as  the  pattern  is  clear  of  the 
mold,  it  is  rolled  back  to  its  original  position,  a  new  flask  placed 
on  the  machine,  and  the  operations  repeated.  An  advantage  of 
this  type  of  machine  is  that  it  can  be  kept  at  work  continuously, 
as  the  completed  mold  can  be  removed  by  a  couple  of  laborers 
at  their  convenience  while  the  molder  is  ramming  up  the  new 
mold.  The  occupation  of  the  cradle  by  the  completed  mold 
does  not  interfere  in  the  least  with  the  operations  of  the  molder 
in  making  a  second  mold. 


MOLDING     MACHINES 


199 


When  the  molds  to  be  made  on  this  type  of  machine 
become  of  large  size,  it  is  beyond  the  ability  of  the  molder  and 
his  helper  to  roll  over  the  heavy  flask  full  of  sand  by  hand,  or 
to  withdraw  the  pattern  by  hand.  In  such  cases  a  power 
cylinder  operated  by  compressed  air  is  added,  as  shown  in 


FIG.   136. — POWER  ROLL-OVER  AND  POWER  DRAFT  MOLDING  MACHINE. 

Fig.  136,  to  perform  these  operations.  Otherwise  the  making 
of  the  molds  is  carried  on  exactly  as  before.  A  still  further 
development  of  this  type  of  machine  is  the  addition  of  a 
jarring  machine  to  the  power  roll-over  attachment,  for  ram- 
ming the  molds.  This  combination  givec  a  machine  of  the 


2OO 


FOUNDRY    PRACTICE 


TABLE  I — DESCRIPTION'  OF    OPERATION    MOLDING    DRAG  AND     COPE 
(PART  OF  PLOW) 

Flask  13"  x  17".     4"  Drag,  \\"  Cope.    Hand  Molding  at  Bench 


Detailed   Instructions 


Element  Time 

per  Piece  Hand 

Mold 


1  I   Preparation 

2 I  

3        i  

4  Pick  up  hard-sand  match  and  put  on  bench I  0.04 

5  Pick  up  pattern  and  put  on  hard-sand  match o .  04 

6  Pick  up  drag  and  put  in  place o .  07 

7  Shake  parting  on  pattern 0.08 

8  Pick  up  riddle  and  put  on  flask o .  02 

9  Fill  riddle  with  sand,  one  shovel  full 0.04 

10  Riddle  sand  on  pattern 0.08 

11  !  Fill  drag  with  sand  (three  shovels  full) 0.08 

12  Peen  around  edge  of  drag  and    butt  ram  some.1 

(With  shovel  butt.) |  o.  10 

13  j   Put  two  more  shovels  full  in  drag 0.06 

14  i   Butt  ram o .  30 

15  j  Strike  mold  off  with  bar,  %Xi  X3&  in.  long o.  10 

1 6  j   Pick  up  bottom-board  and  place  in  position 0.08 

1 7  :   Roll  mold  over o .  08 

1 8  Remove  hard-sand  match 0.07 

19  Blow  sand  off  mold  (with  bellows)   o .  07 

20  Repeat  operations  6  to  10  inclusive  for  cope o. 29 

21  Fill  cope  with  sand,  4  shovels  full o.  10 

22  Repeat  operations  12  to  15  inclusive  for  cope 0.56 

23  Mark  sprue  hole.     (With  cope  board.) 0.05 

24  (Cut  sprue  hole   0.12 

25  Rap  pattern.     Spike  going  through  sprue  hole  into 

pattern o .  49 

26  Round  sprue  |  o.io 

27  Remove  cope  mold . '  o .  09 

28  Blow  pattern  off  with  bellows |  o .  09 

29  Draw  pattern  from  mold  by  hand I  °-45 

30  Patch  up  mold.     (With  slick.) j  o .  30 

3 1  Close  mold   0.12 

32  i   Remove  snap  flask  from  mold o .  07 

33  Remove  mold  to  floor o .  07 

4.20 

I   Number  four  riddle 

Weight  of  shovel.   ...  ...... .'.".' .' .  ... .  .  .  .  . "5  Ibs. 

Weight  of  sand 16  Ibs.  

Total  weight  21   Ibs.  


MOLDING     MACHINES 


201 


TABLE  II — DESCRIPTION   OF  OPERATION  MOLDING  DRAG   AND  COPE 
(PART  OF  PLOW) 

Flask  13"  x  17".     4"  Drag,  4!"  Cope.      Power  Squeezer 


Detailed  Instructions 


Element  Time 

per  Piece  Mach. 

Mold. 


Preparation 

Pick  up    hard-sand  match    and   put  on   table  of 

machine 0 . 04 

Pick  up  pattern  and  put  on  hard-sand  match 0.04 

Pick  up  drag  and  put  in  place o .  < 

Shake  parting  on  pattern o .  < 

Pick  up  riddle  and  put  on  flask o .  02 

Fill  riddle  with  sand o .  < 

Riddle  sand  on  pattern o . 

Fill  up  drag  (three  shovels  full.) 0.08 

Peen  around  edge  of  drag.     (Butt  of  shovel.)  ....  0.05 

Strike  off  with  board  and  put  in  place 0.07 

Bring  yoke  over  and  squeeze  (sixty  Ibs.  pressure.)..  .  0.06 

Roll  mold  over.    (On  table.) .  0.08 

Start  vibrator  and  remove  hard-sand  match o .  03 

Blow  off  with  compressed  air 0.05 

Repeat  operations  from  7  to  1 1  inclusive  for  cope.  .  o.  29 

Fill  up  cope,  four  shovels o.  10 

Repeat  operations  13,  14,  and  15  for  cope o.  18 

Remove  cope  board o .  03 

Blow  mold  off  with  compressed  air o .  05 

Cut  sprue  hole o .  08 

Start  vibrator  and  lift  cope  0.12 

Blow  mold  off  with  compressed  air o .  05 

Start  vibrator  and  draw  pattern o.  10 

Close  mold 0.12 

Remove  flask o .  07 

Stop  off  carrier o .  06 

Place  mold  on  floor o .  06 

2.10 

Number  four  riddle 

Weight  of  shovel 5  Ibs. 

Weight  of  sand 16  Ibs. 

Total  weight 21   Ibs. 


2O2  FOUNDRY   PRACTICE 

highest  efficiency  and  one  which  saves  in  not  only  the  ramming 
but  the  finishing  time,  and  which  has  an  output  far  in  excess  of 
anything  possible  by  other  means.  It,  however,  is  adapted 
for  situations  where  there  are  a  vast  number  of  heavy  and 
complicated  castings  of  similar  size  and  shape  to  be  made. 

When  to  Use  a  Molding  Machine. — The  question  of 
whether  or  not  the  use  of  a  molding  machine  would  pay  can 
be  decided  accurately  only  by  means  of  a  detailed  time-study 
of  the  various  operations  of  making  a  mqld  by  hand  and  by 
machine.  This  time-study  would  show  the  amount  of  time 
saved  by  the  machine  and  it  is  then  simply  a  question  of 
whether  there  are  sufficient  castings  to  be  made  from  a  given 
pattern,  the  total  saving  on  which  would  aggregate  a  sufficient 
amount  of  time  to  warrant  the  expense  of  the  machine.  It 
should  be  borne  in  mind  in  this  connection  that  a  molding 
machine  can  usually  be  run  by  lower-priced  men  than  are 
required  for  making  molds  by  hand.  An  instance  of  a  time- 
study  on  hand  molding  and  on  machine  molding  of  the  same 
pattern  was  given  by  Mr.  Wilfred  Lewis,  in  a  lecture  before 
the  Franklin  Institute  in  April,  1911.  With  his  permission, 
the  author  presents  these  time-studies  together  with  Mr. 
Lewis's  comments  thereon.  (See  pages  200-201). 

In  the  tables  the  time  given  for  each  individual  operation 
is  in  hundredths  of  a  minute.  By  carefully  timing,  with  a 
stop-watch,  each  operation  of  making  a  mold,  it  can  quickly 
be  observed  what  motions  are  unnecessary  and  by  comparing 
the  time  study  of  the  hand  mold  with  that  of  the  machine 
mold,  it  is  easily  determined  the  amount  that  can  be  saved 
by  one  method  as  compared  with  the  other.  In  the  two  tables 
presented,  the  time  for  molding  a  part  of  a  plow  in  a  flask  13  by 
17  inches,  with  a  4-inch  drag  and  a  4^-inch  cope,  both  by 
machine  and  by  hand  is  given.  Comparing  these  two  tables, 
it  will  be  seen  that  items  4  to  1 1  [the  item  numbers  here 
refer  to  the  table  of  hand  molding]  must  be  done  in  the  same 
way  and  will  consume  the  same  amount  of  time,  0.05  minute, 
whether  the  mold  is  made  by  hand  or  by  machine.  Item  12 
must  be  done  more  thoroughly  and  consumes  more  time  in 


MOLDING    MACHINES  2O3 

hand  molding,  and  item  13  is  not  required  at  all  in  machine 
molding.  Item  14,  butt-ramming,  0.30  minute,  is  equivalent 
to  squeezing  by  power  but  consumes  five  times  the  time. 
Item  15,  striking  off,  is  performed  after  ramming,  and  requires 
0.03  minute  longer  than  striking  off  the  unrammed  sand  on 
the  machine.  Item  16  is  not  required  in  machine  molding. 
Item  17,  rolling  over,  is  the  same  in  both  cases.  Items  18  and 
19  require  0.14  minute,  compared  with  0.08  minute  when 
compressed  air  is  used  on  the  power  machine.  Items  20  and  21 
are  identical  for  hand  or  power  molding.  Item  22  requires 
0.56  minute  against  0.18  by  power.  Item  23  is  not  performed 
by  power  as  a  separate  operation  and  item  24  is  the  same  in 
both  cases.  Rapping  the  pattern,  item  25,  requires  0.48 
minute  as  compared  to  0.12  minute,  consumed  in  starting  the 
vibrator  and  lifting  the  cope  at  one  operation  on  the  machine. 
Item  26  is  the  same  in  both  cases.  Item  27,  removing  the 
cope  requires  0.69  minute.  Item  28,  to  blow  off  the  pattern, 
requires  0.04  minute  longer  with  bellows  than  with  compressed 
air  and  drawing  the  pattern,  item  29,  requires  0.35  minute 
longer  in  hand  molding  than  by  machine.  Item  30,  patching, 
requiring  0.30  minute  is  not  called  for,  in  machine  work. 
Items  31,  32,  and  33  are  the  same  in  both  cases,  and  in  mold- 
ing with  the  machine  an  additional  operation,  stopping  off 
the  carriers,  0.06  minute  is  required.  The  total  time  required 
for  making  a  mold  by  hand  is  4.20  minutes,  whereas  the 
machine  will  do  it  in  2.10  minutes  or  exactly  one-half  the 
time.  Should  a  vibrator  be  used  on  the  patterns  in  making 
the  mold  by  hand,  the  total  molding  time  will  be  consider- 
ably reduced,  but  still  enough  in  excess  of  the  machine  time 
to  warrant  the  installation  of  machines,  provided  the  cast- 
ing is  to  be  made  in  sufficient  quantities.  Similar  studies 
to  the  above,  if  made  on  any  class  of  molding,  will  soon  tell 
the  best  method  of  work.  Time  studies  may  also  be  applied 
to  two  different  methods  of  hand  molding  or  two  different 
methods  of  machine  molding  to  ascertain  which  is  the  most 
economical. 


CHAPTER  XX 

MENDING  BROKEN  CASTINGS 

CASTINGS  are  frequently  broken  in  service  or  they  may  have 
some  portion  defective  when  made.  Unless  the  break  is  a 
very  bad  one  or  the  defective  portion  of  wide  extent  it  is 
possible  to  repair  the  casting  by  one  of  a  number  of  methods. 
Up  to  comparatively  recent  times  the  only  method  of  making 
such  repairs  was  by  means  of  the  process  of  burning.  More 
recently,  however,  the  Thermit  process  and  the  oxy-acetylene 
flame  have  placed  in  the  hands  of  the  foundrymen  new  tools 
of  high  efficiency. 

The  process  of  burning  a  casting  is  shown  in  Fig.  137. 
Assume  that  a  casting  with  a  small  projecting  arm  D  has  had 
this  arm  broken  as  shown.  The  two  parts  are  bedded  into 
the  floor  and  a  parting  made  exactly  as  would  be  done 
in  ramming  up  a  pattern.  A  shallow  cope  is  set  over  the 
broken  casting  and  its  position  fixed  by  means  of  stakes,  after 
which  parting  sand  is  riddled  on  the  joint  and  two  gate-sticks 
set,  one  a  little  longer  than  the  other,  on  either  side  of  the  break. 
The  cope  is  then  rammed  up  and  lifted  off  and  the  small 
broken  part  rapped  and  drawn  from  the  mold.  The  broken 
end  is  then  ground  off  for  a  distance  of  about  one-quarter 
inch  and  the  surface  nicked  all  over  with  a  chisel.  This  piece 
is  now  returned  to  its  place  in  the  mold  and  a  sprue  is  cut 
between  the  two  vertical  gates  leading  to  the  space  between 
the  broken  ends  of  the  arm.  The  cope  is  then  replaced,  the 
gate-sticks  withdrawn,  and  by  means  of  snap-flask  weights  A, 
a  deep  pouring  basin  is  built  above  the  smaller  gate  B  and  an 
outflow  H  is  built  over  the  larger  gate  G,  this  outflow  leading 
to  a  large  basin  /. 

The  theory  of  burning  broken  castings  involves  the  flowing 
through  the  break  of  very  hot  iron  which  will  eventually  fuse 
204 


MENDING  BROKEN  CASTINGS 

•^eights 


2O5 


Keadj  focburnJnj 


FIG.  137. — MENDING  A  BROKEN  CASTING  BY  BURNING. 


2O6  FOUNDRY   PRACTICE 

the  ends  of  the  broken  casting,  and  then  allowing  the  casting 
to  cool  together  with  the  iron  which  has  been  poured  through 
the  break.  The  broken  parts  and  the  fresh  iron  will  then 
be  found  to  have  solidified  in  a  firm  homogeneous  mass.  The 
surplus  iron  around  the  break  is  chipped  off  and  the  repaired 
casting  is  as  serviceable  as  one  that  has  never  been  broken. 
The  inflowing  gate  is  made  considerably  smaller  than  the  out- 
flow in  order  that  the  iron  may  flow  freely  through  the  break. 
Should  it  be  retarded  in  its  flow  it  is  liable  to  chill  and  fail 
to  melt  the  ends  of  the  broken  casting,  in  which  case  a  hard 
glazed  surface  would  be  formed  which  would  be  more  difficult 
of  repair  than  the  original  break.  It  is  also  important  that 
the  pouring  basin  be  at  a  considerable  elevation  above  the 
outflow  gate  in  order  that  there  may  be  a  high  head  to  cause 
the  iron  to  flow  rapidly  through  the  break.  Care  must  be 
taken  that  the  ends  of  the  break  are  given  a  sharp  jagged 
surface  as  the  molten  iron  will  not  fuse  a  smooth  surface  so 
readily. 

If  the  casting  is  of  such  shape  that  it  cannot  be  readily 
removed  from  the  sand  as  in  the  case  just  described,  grooves 
may  be  cut  through  the  break  by  a  milling  machine  or  chisel 
and  after  the  sprues  are  cut  the  sand  is  carefully  blown  from 
these  grooves  and  the  cope  replaced  and  the  operation  pro- 
ceeds as  before.  If  a  portion  of  a  casting  of  cylindrical  section 
is  lost,  it  can  be  repaired  by  bedding  the  casting  in  the  sand  and 
making  a  cylindrical  mold  above  the  broken  portion,  the 
mold  being  made  of  sufficient  depth  to  allow  for  a  shrink- 
head,  after  which  a  sufficient  quantity  of  iron  is  allowed  to 
flow  through  the  mold  to  fuse  the  end  of  the  casting  and  it  is 
then  permitted  to  solidify. 

It  is  not  possible  to  repair  breaks  of  every  character  by 
this  method.  The  burning  on  of  a  corner  or  an  arm  is  usually 
accomplished  with  but  little  trouble.  To  burn  metal  into  a 
hole  in  the  centre  of  a  casting,  particularly  if  the  latter  be  thin, 
is  a  more  difficult  proposition.  The  actual  burning  operation 
is  accomplished  easily,  but  trouble  is  encountered  when  the 
repair  cools.  The  unequal  shrinkage  of  the  liquid  metal  and 


MENDING   BROKEN   CASTINGS  2O7 

the  moderately  heated  solid  casting  surrounding  it  renders  it 
difficult  to  make  a  perfect  joint  between  the  two  parts  and 
the  new  metal  frequently  pulls  away  from  the  old.  This 
trouble  may  sometimes  be  remedied  by  preheating  the  metal 
of  the  casting  up  to  about  400°  Fahr.  before  burning,  and 
placing  the  repaired  casting  in  an  oven  of  this  temperature 
as  soon  as  the  burn  is  made,  and  cooling  it  gradually. 

Another  method  of  burning  is  to  surround  the  break  with 
dry-sand  cores  about  an  inch  above  the  casting,  an  outlet  being 
cut  in  the  core  so  that  hot  iron  can  be  poured  directly  on  the 
break  and  flow  off  over  a  notch  cut  in  the  core.  From  one 
hundred  to  one  hundred  and  fifty  pounds  of  very  hot  iron  is 
poured  in  a  thin  stream  on  the  break  and  around  the  place  to 
be  mended.  By  means  of  a  small  rod  the  action  of  the  iron  is 
ascertained.  This  method  is  usually  practiced  on  flat  surfaces. 

The  iron  used  in  repairing  breaks  in  this  manner  must 
be  extremely  soft,  especially  if  the  casting  is  to  be  ma- 
chined later.  The  higher  the  combined  carbon  in  the  iron 
the  harder  will  be  the  burned  spot.  The  iron  in  the  cast- 
ing itself  affects  to  some  extent  the  quality  of  the  iron  in 
the  break. 

Thermit  Welding. — The  introduction  of  the  Thermit 
process  has  rendered  possible  the  repair  of  broken  castings 
which  was  impossible  under  the  older  method.  Thermit  is  a 
mixture  of  fine  aluminum  filings  and  iron  oxide,  which,  when 
set  on  fire,  gives  a  temperature  of  about  5,000°  Fahr.,  the  alumi- 
num uniting  with  the  oxygen  of  the  iron  oxide.  There  is  thus 
formed  a  very  pure  iron  and  a  slag  consisting  principally  of 
aluminum  oxide.  If  this  is  allowed  to  flow  on  a  casting  the 
intense  heat  will  melt  the  casting  wherever  the  mixture  comes 
in  contact  with  it  and,  on  cooling,  the  iron  from  the  Thermit 
will  unite  with  the  iron  of  the  casting  and  form  a  homogeneous 
uniform  mass.  It  is  this  feature  that  is  taken  advantage  of 
in  the  making  of  repairs  to  broken  castings  by  means  of 
Thermit.  A  typical  repair  by  this  method  is  that  of  a  loco- 
motive driving-wheel  with  broken  spokes.  The  wheel  is  laid 
on  the  floor  and  the  broken  parts  are  placed  as  nearly  in  their 


2O8  FOUNDRY   PRACTICE 

original  position  as  possible  with  a  small  space  left  between 
them  at  the  break.  A  mold  is  formed  around  the  break,  the 
parts  of  which  are  heated  with  an  oil  burner.  After  they  have 
been  brought  to  the  proper  temperature  the  funnel  containing 
Thermit  is  placed  over  the  part  to  be  repaired,  a  steel  plug 
being  inserted  at  the  bottom  of  the  funnel.  A  special  ignition 
powder  is  set  on  top  of  the  Thermit  and  lighted  and  after 
the  combustion  of  the  Thermit  is  complete  the  plug  is  pushed 
up  into  the  funnel  and  the  iron  which  has  been  formed  by  the 
combustion  of  the  Thermit  is  allowed  to  flow  down  over  the 
break,  the  slag  flowing  into  a 'basin  made  to  receive  it.  Repairs 
made  by  this  method  are  extremely  strong,  frequently  being 
of  greater  strength  than  the  original  casting.1 

Oxy-acetylene  Welding. — Welding  by  means  of  the 
oxy-acetylene  flame  has  been  successfully  used  in  the  repair 
of  many  difficult  castings.  Acetylene  gas  when  burned  in  a 
blow-pipe  with  oxygen  gives  the  highest  temperature  known 
excepting  the  electric  arc,  approximating  6,000°  Fahr.  This 
flame  can  be  regulated  so  that  it  may  be  drawn  down  to  a  fine 
point  which  localizes  the  heat  generated  by  it  to  a  very  limited 
area.  It  is  this  fact  that  makes  possible  its  use  in  the  repair 
of  castings.  The  broken  parts  are  brought  together  and  a 
groove  is  chipped  along  the  break,  the  sides  of  the  grooves  hav- 
ing an  angle  of  about  forty-five  degrees  from  the  vertical.  The 
oxy-acetylene  flame  is  played  on  this  groove  until  the  metal  in 
it  is  fused.  A  soft  iron  wire  is  then  melted  by  placing  its  end 
in  the  groove  and  allowing  the  flame  from  the  oxy-acetylene 
torch  to  play  upon  it,  when  it  unites  with  the  metal  fused  from 
the  casting.  On  cooling  the  break  will  be  found  to  be  repaired 
quite  perfectly  and  the  strength  of  the  repaired  joint  will 
approximate  from  85  to  100  per  cent,  of  the  strength  of  the 
original  casting.  Considerable  care  is  required  in  the  manipu- 
lation of  this  process  and  detailed  directions  are  given  for  the 
use  of  the  apparatus  by  the  makers.  These  directions  would 

1The  use  of  Thermit  is  covered  by  United  States  and  foreign 
patents  and  complete  directions  for  its  use  should  be  obtained  from  the 
owners  of  the  American  rights,  the  Goldschmitt  Thermit  Co.,  New  York. 


MENDING   BROKEN   CASTINGS  2O9 

be  out  of  place  here  and  the  reader  is  advised  to  consult  with 
the  manufacturers  of  this  apparatus  before  attempting  to 
make  use  of  this  process.  The  leading  manufacturers  of  this 
apparatus  are  the  Davis-Bournonville  Company,  New  York, 
The  Nelson  Goodyear  Company,  New  York,  and  the  Linde 
Air  Products  Company,  Buffalo. 
14 


CHAPTER   XXI 

MOLDING  TOOLS 

THE  tools  most  commonly  used  by  molders  are  shown  in 
the  illustrations  Figs.  138  and  139. 

The  shovel  is  used  for  cutting  up  the  sand  heap  and  for 
filling  the  flask. 

The  water  pail  is  used  for  supplying  water  to  wet  down  the 
sand  for  tempering  and  also  for  wetting  the  swab  or  bosh  on 
the  floor  molding. 

The  riddle  is  a  sieve  used  for  sifting  the  sand  on  to  the 
surfaces  of  the  pattern  when  starting  a  mold.  The  size  of  the 
riddle  is  given  by  the  number  of  meshes  to  the  running  inch. 
Thus,  a  No.  8  riddle  has  eight  meshes  to  the  inch  and  a  No. 
4  riddle,  four.  The  particular  riddle  used  depends  on  the 
character  of  casting  to  be  made,  the  finer  castings  with  con- 
siderable detail  on  their  surface  requiring  finer  sand  and,  there- 
fore, a  finer  riddle. 

Rammers,  used  for  pounding  the  sand  around  the  pattern 
in  the  flask,  are,  for  the  heavier  class  of  castings,  made  of  iron, 
although  sometimes  they  are  made  with  a  wooden  handle 
with  a  cast-iron  butt  at  one  end  and  a  cast-iron  peen  at  the 
other  end.  The  small  rammers  used  in  bench  work  are  usually 
made  of  maple,  although  sometimes  they  are  made  of  cast-iron. 

The  strike  is  used  to  scrape  the  extra  sand  not  wanted  from 
the  top  of  the  cope  or  drag  and  also  for  leveling  the  loose  sand 
placed  in  the  bottom  of  the  larger  drags  before  placing  the 
bottom-board.  It  is  usually  a  thin  strip  of  bar  iron,  two  to 
three  inches  wide. 

Clamps,  used  for  holding  together  the  cope  and  drag  of 
the  completed  mold  or  for  clamping  together  the  mold-board 
and  the  bottom-board  on  either  side  of  the  drag  when  the  latter 
is  rolled  over,  are  of  many  styles  and  sizes.  They  are  shown 


MOLDING  TOOLS  211 

at  6,  7,  and  8  of  Fig.  138.  They  are  made  of  either  wrought- 
iron  or  cast-iron  and  are  wedged  on  the  flask  by  means  of  the 
wooden  wedges  10.  The  wedges  for  side-floor  use  are  usually 
of  soft  wood  and  for  the  heavier  work  either  of  hard  wood  or 
iron. 

The  bellows,  11,  are  used  to  blow  parting  sand  from  the 
pattern  and  also  to  blow  loose  sand  and  dirt  from  the  mold. 

Gaggers  are  L-shaped  pieces  of  wrought  or  cast  iron.  They 
are  shown  at  12,  Fig.  138,  and  are  used  to  hold  up  deep  pockets 
of  sand  in  the  mold,  which,  if  unsupported,  would  fall  of  their 
own  weight.  The  gaggers  are  clay-washed  and  the  friction 
of  them  against  the  body  of  the  sand  is  sufficient  to  prevent 
them  falling  on  account  of  the  weight  of  sand  on  the  pocket 
they  are  supporting. 

Soldiers  are  sticks  of  wood  of  varying  thickness,  used  for 
much  the  same  purposes  as  gaggers.  In  certain  places,  they 
will  hold  up  sand  better  than  gaggers  and  can  be  used  in 
pockets  in  many  places  where  gaggers  would  be  impracticable. 

Trowels,  shown  at  14,  15,  and  16,  Fig.  139,  are  of  many 
different  styles  and  sizes  to  suit  the  individual  taste  of  the 
molo!er.  In  floor  work,  the  trowel  is  used  for  making  the  joint 
on  a  mold,  and  it  is  used  in  all  classes  of  work  for  finishing, 
smoothing,  and  slicking  the  flat  surfaces  of  the  mold. 

Vent-wires  are  shown  at  17,  18,  and  19,  being  steel  wires, 
upset  on  one  end  and  having  a  handle  on  the  other.  They 
are  used  to  perforate  the  mold  to  permit  the  escape  of  gases 
from  it  when  the  casting  is  poured.  They  are  also  used. to 
form  holes  for  gas  to  escape  from  cores  in  the  mold  to  the 
outside  of  the  mold. 

The  bosh  or  swab,  20,  is  made  of  hemp,  teazled  out  to  a 
point  at  one  end  and  bound  with  twine  at  the  other  to  hold  it 
together.  It  is  used  to  flow  a  small  amount  of  water  around 
the  edge  of  the  pattern  in  the  sand,  before  the  pattern  is 
rapped  for  drawing  from  the  mold.  The  bosh  will  hold  con- 
siderable water  and  the  amount  which  it  delivers  to  the  sand 
can  be  regulated  by  the  pressure  the  molder  applies  when 
squeezing  it.  Boshes  are  also  used  to  apply  wet  blacking  to 


212  FOUNDRY   PRACTICE 

dry-sand  molds  when  they  are  to  be  blacked  green,  that  is 
before  the  mold  is  dried,  and  the  blacking  slicked. 

The  soft  brush,  21,  is  used  to  brush  off  the  pattern  and 
the  joint  of  the  mold.  The  hard  brush,  51,  is  used  to  spread 
beeswax  or  tallow  on  metal  patterns  and  to  brush  and  clean 
out  between  the  teeth  of  gears  and  similar  patterns. 

The  rapping  and  clamping  bar,  22,  is  usually  a  bar  of  steel 
from  three-quarters  to  seven-eighths  inch  diameter  and  two 
feet  long.  It  is  pointed  at  one  end  to  enter  rapping 
plates  in  a  pattern  and  is  flattened  and  turned  up  at  the 
other  end  for  convenience  in  tightening  clamps  on  a  flask. 
For  rapping  large  patterns,  the  size  of  the  bar  is  of  course 
increased. 

Draw-screws,  23,  24,  and  25,  are  eye-bolts  threaded  on  one 
end.  They  are  used  for  drawing  large  wooden  patterns  from 
the  sand,  being  screwed  into  holes,  left  for  that  purpose,  in 
the  pattern.  They  are  also  used  for  drawing  metal  patterns. 

The  draw-spike,  26  and  27,  is  a  piece  of  steel,  sharpened  at 
one  end  for  driving  into  a  wooden  pattern  to  rap  and  draw  it. 
It  is  principally  used  in  bench  work  for  drawing  small  patterns. 

Lifters,  28,  29,  30,  are  used  for  clearing  of  loose  sand  deep 
places  in  molds.  They  are  of  different  lengths  and  sizes,  one 
end  being  turned  at  right  angles  to  the  stem,  this  portion 
being  termed  the  heel.  The  straight,  flattened  portion  is 
known  as  the  blade.  The  blade  and  heel  are  also  used  to 
slick  the  sides  of  the  mold  where  they  cannot  be  reached  in 
finishing  by  the  trowel  or  slicker.  The  heel  is  also  used  to 
slick  the  bottom  of  deep  places  after  the  sand  has  been  re- 
moved. 

Slickers,  31,  32,  and  33,  are  formed  with  blades  of  varying 
widths,  with  the  other  end  of  the  tool  turned  to  form  a  heel 
somewhat  similar  to  the  lifter.  It  is  used  for  lifting  loose  sand 
in  shallow  parts  of  the  mold  and  for  slicking  down  when  patch- 
ing broken  edges.  The  blade  is  used  to  build  sand  on,  to 
form  corners  to  the  proper  shape.  This  tool  is  used  more  by 
molders  than  any  other  except  the  trowel. 

Corner  tools,  34,  are  used  to  slick  the  corners  of  molds 


MOLDING   TOOLS  213 

where  a  slicker  or  the  heel  of  a  lifter  will  not  do  satisfactory 
work.  Corner  tools  are  made  with  different  angles  for  special 
work,  being  usually  formed  of  cast-iron  by  the  molders  and 
polished. 

Bead  slickers,  35  and  36,  are  of  special  shapes  and  sizes. 
They  are  used  to  slick  what  are  termed  beads  or  hollow  places 
in  a  mold.  They  are  usually  made  of  steel  or  composition 
metal  and  seldom  of  cast-iron. 

Flange  tools,  37,  are  used  for  slicking  flanges  on  pipes  or 
cylinders.  The  rounded  ends  of  the  flange  tool  are  made  of 
different  radii  for  use  on  different  flanges.  They  are  usually 
made  of  steel. 

Spoon  slickers,  38  and  39,  have  spoon-shaped  ends  and 
are  used  to  slick  rounding  surfaces  in  a  mold.  They  are 
usually  made  with  one  end  larger  than  the  other. 

Pipe  tools,  40  and  41,  are  used  to  slick  pipe  molds  in  the 
plain  rounding  part.  Some  are  made  as  in  the  illustration 
and  others  are  formed  more  in  the  shape  of  a  spoon.  They  are 
also  used  on  any  cylindrical  work  for  facing  the  interior  of 
cylindrical  surfaces.  They  are  usually  of  cast-iron  with  a 
handle  set  vertically  in  the  center. 

Hub  tools,  43,  44,  45,  and  46,  are  used  in  any  cylindrical 
portion  of  a  mold,  such  as  hubs  of  pulleys  or  other  portions 
which  are  too  small  to  permit  use  of  a  pipe  slicker.  One  end 
is  turned  at  right  angles  for  use  in  lifting  sand  from  the  bottom 
of  the  hub  in  order  to  slick  it.  The  back  of  the  heel  being 
rounded,  the  hub  tool  can  be  brought  in  close  to  the  edge  of 
the  mold  for  finishing.  They  are  made  of  steel  or  composi- 
tion metal. 

The  double- ender ,  47,  comprises  a  slicker  at  one  end  and  a 
spoon  slicker  at  the  other.  They  are  usually  made  to  the 
molder's  order  and  are  used  by  bench  molders  on  small  molds. 

The  earner s-hair  brush,  48,  is  used  to  brush  dry  blacking 
on  the  face  of  the  mold. 

The  wooden  gate-pin,  49,  sometimes  called  a  sprue,  is  a 
round  tapered  pin  used  to  form  the  gate  extending  through  the 
cope  into  which  iron  is  poured  into  the  mold.  They  are  of 


214 


FOUNDRY   PRACTICE 


1 


FIG.   138. — MOLDER'S  TOOLS. 

i,  Shovel;  2.  riddle  or  sieve;  3.  iron  rammer;  4.  tool  box;  5.  strike;  6-8  clamps;  9.  hand 
mer;    10.  wedges;    n,  bellows;    12,  gaggers-    13,  soldiers;    55-56,  calipers,   57.  cul 


MOLDING    TOOLS 


FIG.  139. — MOLDER'S  TOOLS. 

14-16,  Trowels;  17-19,  vent-wires;  20,  bosh  or  swab;  21,  soft  brush;  22.  rapping  or 
clamping  bar;  23-25,  draw-screws;  26-27,  draw-spikes;  28-30,  lifters;  31-32,  slickers; 
34,  corner  tool;  35-36,  bead  slickers;  37,  flange  tool;  38-39,  spoon  slickers;  40-41,  pipe  tools; 
42,  button  tool;  43—46,  hub  tools;  47,  double-ender;  48,  camel's-hair  brush;  49,  wooden 
gate-pin;  50,  rapping  iron;  51,  hard  brush;  52,  spring  draw-nail,  53,  54.  sprue  cu.ters. 


2l6  FOUNDRY    PRACTICE 

the  size  required  by  the  class  of  mold,  and  occasionally  may 
be  square  or  octagonal  in  cross  section. 

The  rapping  iron,  50,  is  used  to  rap  or  jar  gated  patterns 
in  the  mold.  It  is  commonly  used  in  connection  with  the  rap- 
ping bar,  22,  which  is  entered  through  the  hole  in  the  cope 
made  by  the  gate-stick.  The  bar  entering  a  hole  in  the  striking 
gate  on  which  the  patterns  are  soldered,  it  is  struck  with  the 
rapping  iron  to  jar  the  pattern  at  the  same  time  in  both  the 
cope  and  drag. 

The  spring  draw-nail,  52,  is  used  for  drawing  small  patterns. 
It  consists  of  two  pointed  rods,  joined  together  with  a  spring, 
which  forces  the  points  outward.  It  is  used  for  drawing  small 
patterns  by  inserting  the  points  of  the  two  rods  in  a  hole  in  the 
pattern,  the  points  being  pressed  together;  on  releasing  the 
points,  they  spread  apart  and  give  sufficient  grip  on  the  pattern 
to  draw  it. 

The  gate  or  sprue  cutter,  53,  is  a  piece  of  sheet  brass  bent 
to  a  semicircle  on  one  edge.  It  is  used  to  cut  the  channel  in 
the  drag  from  the  hole  left  by  the  gate-stick  to  the  mold. 

Another  form  of  sprue  cutter  is  shown  at  54,  being  a 
cylindrical  metal  tube  used  to  cut  the  gate  in  the  cope  when 
the  gate-stick  has  not  been  used. 

Calipers  are  more  used  by  the  core-maker  than  the  molder. 
The  molder  uses  them  to  verify  the  sizes  of  cores  in  order  to 
make  the  proper  size  of  core-print  and  also  to  obtain  the  length 
of  smaller  cores.  The  calipers  in  this  case  are  set  at  the 
proper  length  and  the  core  filed  to  fit.  This  is  important  in 
dry-sand  work,  since,  as  there  is  no  give  to  a  dry-sand  mold,  it 
will  be  crushed  if  the  core  is  too  large  when  the  mold  is  closed. 

Cutting  nippers,  57,  are  used  to  cut  the  smaller  wires  in 
core-making  to  the  desired  length. 

The  monkey  wrench  is  used  to  screw  down  rod  bolts  to 
hold  binders  with  which  the  mold  is  fastened  and  also  to 
tighten  bolts  in  iron  flasks. 


CHAPTER  XXII 

MOLDING  SANDS 

MOLDING  sand  is  a  sand  possessing  those  qualities  which 
enable  it  to  be  tempered  and  formed  to  definite  shapes  which 
it  will  retain  when  molten  metal  is  poured  in  it,  and  which  has 
the  requisite  chemical  composition  to  enable  it  to  resist  fusion 
from  the  heat  of  the  molten  metal.  Molding  sand  must  also 
have  sufficient  permeability  to  permit  the  free  escape  of  gases 
from  the  mold  while  it  is  filling  with  metal,  without  scabbing 
or  otherwise  injuring  the  surface  of  the  mold.  The  sand  also 
should  be  capable  of  being  retempered  and  used  for  successive 
molds  without  the  addition  of  new  sand  to  provide  bond. 

Molding  sand  is  found  in  large  deposits  in  the  United 
States  in  the  states  of  New  York,  New  Jersey,  Ohio,  Indiana, 
Illinois,  Missouri,  and  Kentucky.  It  is  also  found  in  smaller 
deposits  in  Michigan,  Wisconsin,  Connecticut,  and  Massa- 
chusetts. The  characteristics  of  the  sands  from  these  different 
localities  vary  and  they  are  not  all  suited  to  every  grade  of 
work.  Combinations  or  mixtures  of  sands  from  one  locality 
with  those  from  another,  will  often  give  a  desired  grade  and 
quality  of  molding  sand  when  none  of  the  component  sands  is 
suitable. 

The  principal  requirements  of  a  good  molding  sand  are: 
resistance  to  fusion;  bond;  permeability  and  porosity.  An 
excess  of  lime — one  per  cent  or  more — will  lower  the  power  of 
the  sand  to  resist  fusion.  If  present  as  a  silicate,  it  will  com- 
bine with  the  silica  and  alumina  of  the  sand  under  the  influence 
of  the  heat  of  the  molten  iron,  and  will  vitrify  and  form  a  scale 
on  the  casting.  Permeability,  or  ability  to  permit  the  passage 
through  it  of  gases  formed  in  the  mold  while  filling  with  metal, 
is  one  of  the  most  important  qualities  of  molding  sand.  There 
is  a  difference  between  permeability  and  porosity.  The 
217 


218  FOUNDRY    PRACTICE 

porosity  of  a  sand  is  the  ratio  of  voids  or  pore  spaces  to  the 
total  volume  of  the  sand,  while  the  permeability  depends  on 
the  area  of  the  passage  ways  through  the  sand  formed  by  these 
voids.  Air  fills  the  pores  in  the  mold,  and  this  when  heated 
during  the  pouring  of  the  metal,  expands.  The  sand  must 
have  sufficient  cohesion  or  bond  to  resist  the  pressure  due  to 
this  expansion,  and  it  also  must  have  sufficient  permeability 
to  permit  the  escape  of  the  contained  air  and  of  the  gases 
generated  in  pouring.  The  greater  the  ease  with  which  the 
air  and  gases  escape,  the  less  need  there  is  for  a  strong  bond. 
In  green  sand,  more  or  less  water  is  contained  in  the  mold 
which  is  converted  into  steam  in  casting,  and  this  also  must 
escape.  If  these  various  fluids  cannot  escape  easily  through 
the  mold  or  core,  blow  holes  are  formed  and  the  casting  is 
injured.  A  molding  sand,  therefore,  must  not  only  have 
cohesion  between  its  particles  to  withstand  certain  strains, 
but  it  must  at  the  same  time  possess  the  desired  permeability.1 
The  experiments  of  King2  show  that  the  finer-grained 
sands,  even  when  the  grains  are  approximately  the  same  size, 
have  greater  pore  space  than  the  coarser  sands  when  both  are 
equally  tamped.  The  average  pore  space  of  seven  samples 
of  No.  100  quartz  sand 3  was  36.6  per  cent.,  while  that  of  three 
samples  of  No.  20  sand  was  33.9  per  cent.  The  same  experi- 
ments show  that  sharp,  angular  sands  have  a  greater  pore 
space  than  rounded  sands  of  the  same  size,  indicating  ap- 
parently the  greater  difficulty  of  making  angular  grains  pack 
well.  It  was  also  found  that  the  smallest  pore  space  was 
obtained  when  two  sands  of  rounded  grains,  but  of  quite 
dissimilar  diameters,  were  mixed  in  about  equal  proportions 
by  weight.  The  theoretical  minimum  pore  space  of  sand  with 
spherical  grains  is  25.95  Per  cent.,  and  only  once  in  these  ex- 

1  Annual  Report  of  the  State  Geologist  of  New  Jersey,  1904,  page 
199.      Report  on  molding  sands. 

2  Nineteenth  Annual  Report  of  the  Director  of  the  U.  S.  Geological 
Survey,  II.,  pages  209-215. 

3  Sand  retained  on  a  sieve  with  100  meshes  to  the  inch  but  passing 
an  8o-mesh  sieve. 


MOLDING    SANDS  219 

periments  did  the  pore  space  fall  below  this  minimum.  From 
these  experiments,  the  conclusions  can  be  drawn  that  (A) 
pore  space  can  be  reduced  by  tamping,  but  the  theoretical 
minimum  can  be  reached  but  rarely;  (B)  under  equal  treat- 
ment, mixed  sands  of  different  grain  diameters  give  lower 
pore  space  than  do  sands  of  uniform  grain,  the  degree  of 
rounding  being  the  same;  (C)  angular  sands  have  more  pore 
space  than  rounded  sands,  other  things  being  equal;  (D)  the 
least  pore  space  may  be  expected  when  the  round  grains  are 
about  equally  divided  between  large  and  small  with  no  in- 
termediate sizes.  It  is  evident  that  the  closer  the  packing 
of  the  grains,  the  less  the  permeability,  and,  other  things  being 
equal,  coarse  sands  are  more  permeable  than  fine,  and  angular 
sands  more  so  than  rounded. 

Chemical  analysis,  while  determining  the  amount  of  bond 
in  the  sand,  and  also  its  resistance  to  fusion,  does  not  deter- 
mine whether  or  not  a  good  casting  can  be  produced  with  a 
certain  sand.  Microscopic  tests  are  also  necessary,  as  these 
will  reveal  the  shapes  of  the  grains  of  sand,  whether  the  grains 
are  flattened,  rounded,  or  angular  which  in  turn  determines 
how  closely  the  mold  can  be  rammed  and  still  permit  the  gases, 
generated  in  pouring,  to  escape.  A  sharp  angular  grain  is  of 
the  utmost  importance,  since  with  this  grain  the  sand  can  be 
firmly  rammed  around  the  pattern  and  yet  give  a  porous  and 
permeable  mold.  With  a  strong  open  sand,  a  poor  molder 
will  often  make  a  better  casting  than  will  a  good  molder  using 
a  sand  lacking  in  permeability.  A  molding  sand  with  grains 
nearly  round,  while  making  a  good  mold,  requires  more  atten- 
tion than  the  other. 

If  heavy  castings  are  to  be  made,  the  sand  must  withstand 
a  high  degree  of  heat  for  a  considerable  period  and,  to  resist 
fusion,  a  sand  containing  more  silica  and  less  bond  is  required. 
The  refractoriness  of  sand  depends  upon  its  silica  content,  but 
the  bond  decreases  as  the  silica  increases.  When  the  sand  avail- 
able for  large  castings  is  considered  too  close  in  texture  to  have 
sufficient  permeability  and  refractoriness,  silica  sand  or  ground 
silica  rock  is  sometimes  added  to  open  up  the  molding  sand. 


220 


FOUNDRY    PRACTICE 


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MOLDING   SANDS 


221 


The  table  herewith  has  been  derived  from  the  reports  of 
various  State  Geologists.  It  indicates  the  chemical  composi- 
tion of  various  grades  of  molding  sand  together  with  the  uses 
to  which  they  are  best  adapted. 

TABLE  II  shows  the  analyses  of  molding  sand  from 
different  parts  of  the  United  States.  Of  these  Nos.  I  and  2  are 
stove-plate  sands,  while  3  and  4  are  used  for  general  work. 

TABLE  II 


i 
Per  Cent 

2 

Per  Cent 

3 

Per  Cent 

4 
Per  Cent 

Silica  

79.36 

79.38 

84.40 

85.04 

Alumina 

9^6 

9  38 

7   SO 

5  90 

Ferric  oxide  

3.18 

3  98 

2.52 

3.18 

Lime  

0.44 

i  .40 

O.O6 

0.06 

Magnesia  

0.27 

0.54 

O.2I 

0.14 

Potash  

2.19 

i.  80 

I  .29 

1.65 

Soda 

I    54 

i  04 

O  6s 

o  83 

Titanic  oxide 

o  34 

o  44 

o  44 

0.78 

Water                        .    .    . 

2   O2 

2.50 

1.49 

i  .57 

Moisture  

0.74 

0.80 

1.76 

i.  it 

The  following  analysis  of  a  sand  with  an  angular  grain 
formation  will  prove  a  good  sand  for  stove-plate  work.  For 
light  bench  castings,  however,  it  should  have  more  bond. 


TABLE  III 

Per  Cent 

Silica 80.98 

Alumina 9 . 50 

Oxide  of  iron 3 . 90 

Lime o .  60 

The  following  analyses  of  molding  sands  are  from  the  joint 
report  of  B.  H.  Hamilton  and  H.  B.  Kummel,  on  "Molding 
Sands  of  New  Jersey." 


222  FOUNDRY   PRACTICE 

TABLE  IV 
UNUSED  No.  i  ALBANY  SAND 

Per  Cent 

Silica  (Si02) 80.88 

Alumina  (A12  O3). . .  ) 

Iron   oxide    (Fe2O3)  J   I4'°3 

Lime  (CaCO3) i  .32 

Combined  water 2 . 54 

Specific  gravity 2 . 65 

Pore  space 43 . 3 

Tensile  strength 4.31  Ib.  per  sq.  in. 

Pan,  80;  clay  adhering,  5.5;  fineness,  95.00. 

ALBANY  STOVE-PLATE  SAND 

Pan,  77;  clay  adhering,  I  +  ;  fineness,  95;  specific 
gravity,  2.65;  pore  space,  41.55  per  cent. 

NEW  JERSEY  MOLDING  SANDS 

I.  Sand  for  brass  molding  and  light  malleable  castings — 
pan,  84.5;  clay  adhering,  2.5;  fineness,  95.2;  pore  space,  43 
per  cent. 

II.  Stove-plate  sand — pan,  71.36;    clay  adhering,  0.565; 
fineness,  88.4;  pore  space,  37  per  cent. 

III.  General    foundry  work — pan,    11.5;    clay  adhering, 
3.0;  fineness  72.2;  pore  space,  37  per  cent. 

IV.  Heavy  castings — pan,  13.89;    fineness,  72.2;    specific 
gravity,  2.633;  pore  space,  37  per  cent. 

V.  Lumberton  Loam  No.  II — pan,  44.42;   clay  adhering, 
10.27;  fineness,  85;  pore  space,  47.4  per  cent. 

COXSACKIE  (N.  Y.)  No.  2  SAND 

Pan,  52.52;  clay  adhering,  5.0;  fineness,  83.9;  pore  space, 
33  per  cent. 

The  character  of  casting  to  be  made  governs  the  selection 
of  the  molding  sand  to  be  used.  Small,  thin  castings  for 


MOLDING  SANDS  22$ 

ornamental  work,  having  on  their  surfaces  a  series  of  lines,  de- 
pressions, and  projections,  require  a  very  fine-grained  molding 
sand.  A  coarse  sand,  used  in  this  connection,  will  not  only 
refuse  to  reproduce  the  design  but  will  leave  rough  surfaces 
and  imperfect  lines  on  small  castings.  For  molding  very 
fine  castings  in  bronze,  what  is  known  as  French  sand  is 
necessary.  See  analyses  in  Table  I. 

In  the  United  States  a  sand  known  as  Windsor  Locks 
(Conn.)  is  used  in  making  castings  for  chandelier  and  similar 
fine  composition  work.  A  sand  used  for  bronze,  brass,  or 
other  composition  castings  is  not  subjected  to  as  high  a  tem- 
perature as  that  used  in  iron  casting,  owing  to  the  lower 
melting  point  of  the  composition  metals,  and,  therefore,  cast- 
ings may  be  permitted  to  remain  in  the  mold  until  cooled.  For 
brass  and  small  iron  castings,  a  grade  of  sand  known  as  No. 
oo  Albany  sand  is  frequently  used  instead  of  Windsor  Locks 
sand.  Among  these  classes  of  castings  are  toys,  shelf  hard- 
ware of  the  lighter  kind,  small  novelties,  name-plates,  and  small 
gears.  Sands  of  similar  texture  to  these  two  are  found  in 
Kentucky,  Ohio,  and  Indiana. 

For  somewhat  heavier  castings,  in  general  bench  work, 
No.  o  Albany  sand  is  used.  The  most  commonly  used  sand 
in  the  Eastern  States  is  No.  I  Albany  sand.  It  may  be  used 
for  nearly  all  kinds  of  castings,  both  brass  and  iron  and  for 
castings  of  considerable  size.  When  used  for  composition  or 
brass  castings,  it  is  made  somewhat  drier  than  when  used  for 
iron,  as  composition  metals  will  not  lie  quietly  against  a  damp 
surface  and  a  scabbed  face  will  result.  For  boiler  fronts, 
cab  brackets  for  locomotives,  and  general  light  castings  on 
bench  or  side-floor  work,  cotton  and  woolen  machinery  castings 
and  small  tool  castings,  highly  permeable  sand  should  be  used. 

No.  2  Albany  sand,  or  sand  of  a  similar  grade,  is  largely  used 
for  side-floor  work  alid  for  some  of  the  heavier  castings  molded 
under  a  crane.  It  may  be  used  for  castings  weighing  several 
tons.  As  much  depends  on  the  skill  of  the  molder  as  on  the 
sand  when  making  molds  for  castings  whose  weight  is  measured 
in  tons.  A  scabbed  casting  may  often  result  from  improper 


224  FOUNDRY    PRACTICE 

venting  of  the  mold,  especially  where  the  iron  remains  in  a 
molten  state  for  any  length  of  time  after  pouring.  The  sand 
is  often  blamed  for  poor  results  whereas  they  rightly  should  be 
traced  to  the  ignorance  of  the  molder  in  regard  to  vents  and 
passageways  through  which  gas  may  escape  from  the  mold. 

Lathe  beds,  locomotive  and  small-engine  castings,  made  in 
green  sand,  may  be  molded  in  a  sand  of  similar  analysis  to  that 
of  Coxsackie  No.  2.  Albany  sand  No.  3,  or  Albany  sand  No.  4, 
are  quite  similar  to  this  Coxsackie  No.  2  sand,  although  it  is 
somewhat  coarser.  They  are  used  for  printing-press  frames, 
planer  beds  and  tables,  drop-press  beds,  shear  frames,  beds  for 
stone  crushers,  engine  beds,  and  the  heavier  machine-tool 
castings.  It  is  also  used  as  a  component  in  mixtures  for  skin- 
dried  and  dry-sand  molds  and  for  core-sand  mixtures. 

As  the  sand  becomes  coarser,  its  bonding  properties  which 
give  cohesion  decrease,  and  the  silica  content,  which  aids  in 
resisting  fusion,  increases.  Many  castings  molded  in  green 
sand  remain  in  a  liquid  state  for  a  considerable  period  after 
pouring.  They  also  require  churning,  pumping,  or  feeding  with 
hot  iron,  during  which  period  the  sand  is  constantly  absorbing 
heat  from  the  casting.  Hence,  the  resistance  to  fusion  must 
be  great  and  also  the  cohesiveness  to  prevent  the  sand  crum- 
bling under  the  intense  heat  to  which  it  is  subjected.  It  is  there- 
fore evident  that  the  selection  of  the  proper  grade  of  molding 
sand  for  making  any  given  class  of  castings,  requires  a  knowl- 
edge of  chemical  analysis  and  of  the  granular  formation. 
While  any  of  the  larger  foundry-supply  houses,  as  The  S.  Ober- 
mayer  Co.,  Whitehead  Bros., or  J.  W.  Paxson  &  Co.,  will  supply 
a  good  grade  of  sand  for  any  given  class  of  castings,  the  foun- 
dryman  should  have  a  general  knowledge  of  the  properties  of 
molding  sand  in  order  to  obtain  the  best  results  with  the 
different  classes  of  castings  which  he  is  required  to  make. 

In  making  castings  with  a  very  smooth  surface,  a  sand 
that  has  been  previously  used  will  give  a  better  surface  than 
a  new  sand,  fresh  from  storage.  It  is  presumed,  of  course,  that 
the  used  sand  has  sufficient  strength,  molding  sand  becoming 
"rotten"  or  weakened  by  constant  use.  If  it  is  necessary  to 


MOLDING   SANDS  225 

use  new  sand,  it  is  advisable  to  first  spread  it  on  the  floor  and 
then  flow  molten  iron  over  it  to  burn  it.  The  following  day, 
some  of  the  old  sand  from  the  heap  should  be  mixed  with  this 
sand  and  used  as  a  facing  on  the  mold. 

Molding  sand,  as  it  comes  from  the  pit  where  it  is  mined, 
contains  a  certain  amount  of  vegetable  or  animal  life.  The 
sand  must  be  burned  to  get  rid  of  this.  As  an  instance  of  what 
may  happen  in  an  unburned  sand,  the  case  of  a  large  mold 
which  remained  unpoured  for  a  number  of  days  after  finishing 
may  be  cited.  This  mold  was  made  of  new  sand  and  on  being 
opened,  prior  to  pouring,  it  was  found  that  a  number  of  plants 
were  sprouting  from  the  face  of  the  mold.  Considerable  time 
was  lost  and  no  little  expense  incurred  in  going  over  the  face 
of  the  mold  to  repair  the  damage  caused.  The  importance  of 
properly  preparing  molding  sand,  to  prevent  occurrences  of 
this  character,  is  becoming  recognized  and  machinery  is  now 
on  the  market  for  such  purposes. 

Molding  sand,  after  being  used  a  certain  length  of  time, 
loses  its  bond  or  cohesion.  Every  time  a  casting  is  removed 
from  the  mold,  a  certain  amount  of  sand  adheres  to  it  and 
is  thereby  lost.  New  sand  is  added  to  the  sand  heap,  not  only 
to  make  up  for  this  loss,  but  to  restore  the  bond  to  the  older 
sand.  New  molding  sand  is  of  a  yellowish  or  reddish  yellow 
appearance,  ranging  to  a  deep  reddish  brown  due  to  the 
presence  of  oxide  of  iron.  Molding  sand  which  has  been  used 
gradually  assumes  a  deep  black  color,  due  to  the  presence  of 
the  seacoal  facing  which  is  burned  into  the  sand. 

When  the  sand  heap  becomes  very  black  in  color,  mechani- 
cal tests  should  be  applied  and,  if  found  lacking  in  strength, 
the  sand  should  be  renewed.  A  mold  made  of  sand  of  low 
strength  is  liable  to  have  the  face  washed  from  it  by  the  in- 
flowing iron  or,  in  closing  the  mold,  a  portion  of  the  sand  is 
liable  to  drop. 

Foundrymen  have  many  methods  of  testing  the  physical 

quality  of  molding  sands.     For  instance,  a  foundryman  will 

take  a  handful  of  tempered  sand,  squeeze  it  in  his  hand  to  form 

an  elongated  mass.     He  then  suspends  it  by  one  end  from 

15 


226  FOUNDRY    PRACTICE 

between  his  thumb  and  forefinger.  If  it  breaks  off  from  its 
own  weight,  it  is  not  considered  a  strong  sand.  If,  however, 
it  hangs  together,  thus  indicating  strength,  there  may  be  an 
excessive  amount  of  clay  present.  Therefore,  a  small  portion 
is  wet  and  rubbed  between  the  thumb  and  forefinger,  the 
amount  of  clay  being  judged  from  the  stickiness  of  the  sand 
as  shown  in  this  operation.  Frequently,  an  open  mold  is  made 
of  the  sand  under  consideration  and  after  feeling  it  to  deter- 
mine the  hardness,  iron  is  poured  on  it  and  its  action  observed. 
The  test  gives  a  very  close  estimate  of  the  value  of  the  sand. 
While  these  different  tests  have  their  value  to  the  experienced 
foundrymen,  they  are  not  in  any  case  equal  to  a  microscopic 
and  chemical  examination  of  the  sand.  Generally,  if  a  sand  in 
use  in  a  foundry  is  satisfactory  to  those  in  charge  of  the  prac- 
tical operations,  it  is  unwise  to  change,  as  there  is  considerable 
liability  of  many  castings  being  lost  before  the  molders  become 
accustomed  to  the  new  sand. 

The  report  of  the  Board  of  Geological  Survey  of  the  State 
of  Wisconsin,  in  1907,  says  regarding  molding  sands:  "Un- 
fortunately no  standard  method  of  examination  or  testing 
has  been  adopted  by  the  foundrymen,  much  as  this  is  to  be 
desired.  A  few  buy  their  sand  on  the  basis  of  composition; 
others  specify  sands  of  a  certain  texture  or  both  texture  and 
composition  may  be  considered.  The  majority  of  foundry- 
men,  however,  depend  upon  the  judgment  of  their  foreman 
who,  in  many  cases,  uses  empirical  methods  for  determining 
the  value  of  the  material.  If  the  fears  expressed  by  many 
foundrymen  are  well  founded,  the  time  may  not  be  far  distant 
when  the  supply  of  high-grade  sands  will  be  exhausted  and  the 
production  of  artificial  materials,  by  the  admixture  of  sand 
and  clay,  will  be  necessary." 

Preparation  of  Sand  for  Molding.— After  the  flasks  in 
which  the  previous  day's  castings  were  made  have  been 
shaken  out  and  the  castings  removed  from  the  sand,  the  sand 
is  wet  down.  The  molder  or  his  helper  do  this  with  a  pail  of 
water,  throwing  the  pail  around  in  a  circular  path  and  tipping 
it  so  that  the  water  will  fly  over  the  edge  on  one  side  and  form 


MOLDING   SANDS  22 7 

a  thin  sheet  covering  quite  an  area.  This  operation  is  con- 
tinued until,  in  the  judgment  of  the  molder,  the  sand  is 
sufficiently  damp.  If,  in  molding  on  the  previous  day,  the 
sand  has  shown  insufficient  strength,  new  molding  sand  is  at 
this  point  added  to  the  heap,  it  being  spread  over  the  entire 
surface.  The  sand  is  then  "cut  over"  with  the  shovel.  As 
each  shovelful  of  sand  is  thrown,  a  twist  is  given  to  the  shovel 
to  spread  the  sand  as  much  as  possible.  Lumps  are  broken 
up  with  the  flat  or  under  side  of  the  shovel.  Any  dry  portions, 
which  are  encountered  in  cutting  the  sand,  are  moistened,  care 
being  taken  to  avoid  making  the  sand  too  wet.  An  excess  of 
moisture  in  the  sand  will  cause  the  metal  in  the  mold  to  bubble 
or  "kick,"  whereas  sand  that  is  too  dry  will  crumble  when  the 
pattern  is  drawn.  It  is  difficult,  if  not  impossible,  to  describe 
a  properly  tempered  sand,  which  is  determined  by  the  sense  of 
touch  of  the  molder.  This  can  be  acquired  only  by  experience. 

As  sand  may  remain  in  a  flask  for  some  little  time  after 
the  mold  has  been  poured,  it  may  bake  hard  in  the  flask. 
When  the  mold  is  shaken  out,  the  sand  will  be  found  to  have 
formed  in  a  mass  of  large  and  small  lumps.  These  must  be 
broken  up  before  water  is  applied,  otherwise  moisture  will 
not  soak  in  when  the  sand  is  wet  down.  The  effect  of  not 
breaking  these  lumps  becomes  evident  when  molding.  If  one 
of  these  lumps  is  broken  up  while  sand  is  being  riddled  over 
the  pattern,  a  small  shower  of  dry  sand  will  fall  into  the  mold 
and  will  fail  to  cohere  to  the  tempered  sand.  The  result  will 
be  a  rough,  a  broken  casting.  The  more  thoroughly  sand  is 
tempered  and  cut  over,  the  more  easily  it  will  be  worked  by 
the  molder. 

Information  regarding  the  molding  sands,  fire  sands,  and 
fire-clay  of  various  States,  can  be  obtained  from  the  State 
Geologists  and  Mineralogists.  The  more  important  reports 
on  these  subjects  are  as  follows: 

Pennsylvania.  "Report  of  Topographic  and  Geologic 
Survey  Commission,  1906-1908."  "Annual  Report  of  the 
Secretary  of  Internal  Affairs,  Pennsylvania,  Part  III,  Indus- 
trial Statistics,  1907." 


228  FOUNDRY    PRACTICE 

Wisconsin.  "Bulletin  15.  The  Clays  of  Wisconsin  and 
Their  Uses." 

Michigan.  "Report  of  the  State  Board  Geological  Sur- 
vey, 1907." 

New  Jersey.  "Report  of  the  Geological  Survey  of  New 
Jersey,  1904." 

New  York.  "Clay  Industries  of  New  York,  1895."  H. 
Ries.  "Clays  of  New  York;  Their  Properties  and  Uses."  H. 
Ries.  "Mining  and  Quarry  Industry  of  New  York."  D.  H. 
Newland,  1905,  1906.  "Mining  and  Quarry  Industry  of  New 
York,  1906,  July,  1907."  "Mining  and  Quarry  Industry  of 
New  York."  D.  H.  Newland,  1907,  1908. 

Missouri.  "Missouri  Geological  Survey  Report.  Sand 
and  Clays."  Wheeler. 

FACING  MATERIALS 

For  forming  the  surface  of  molds,  it  is  often  necessary  to 
use  a  different  material  from  molding  sand.  There  are  many 
facings  on  the  market,  the  more  common  ones  being  seacoal, 
plumbago,  powdered  charcoal,  talc,  and  gashouse  carbon. 

Seacoal. — Seacoal  is  a  facing  made  from  bituminous  coal. 
It  obtained  its  name  from  the  fact  that  coal  was  formerly 
brought  to  London  by  sea,  and  became  known  as  seacoal  in 
contradistinction  to  coal  brought  in  overland.  The  name  has 
clung  to  it,  although  in  a  strict  sense  it  is  meaningless. 

Most  of  the  seacoal  facing  manufactured  in  this  country  is 
made  from  coal  mined  in  Westmoreland  County,  Pa.  A  good 
gas  coal  is  required  for  manufacturing  first-class  seacoal  facing, 
as  it  must  contain  a  high  percentage  of  volatile  matter,  with 
a  low  percentage  of  ash  and  other  impurities.  The  writer 
is  indebted  to  the  S.  Obermayer  Co.  for  the  following  in- 
formation regarding  seacoal :  Coal  of  approximately  the  fol- 
lowing analysis  is  used:  Fixed  carbon,  60.52  per  cent.;  water, 
1.37  per  cent.;  volatile  matter,  34.75  per  cent.;  sulphur,  0.678 
per  cent.;  ash,  21.675  Per  cent.  The  coal  is  prepared  by  being 
ground,  screened,  and  bolted  to  the  degree  of  fineness  desired. 

For  use  in  molds  for  the  heavier  castings,  most  foundrymen 


MOLDING    SANDS  22Q 

prefer  it  ground  to  what  is  termed  "gunpowder."  This  grade 
is  also  used  on  medium  crane,  and  heavy  side-floor  work.  The 
finest  ground  and  bolted  seacoal  facing  is  used  on  light  work 
where  intricate  designs  are  traced  on  the  face  of  the  pattern. 
Seacoal  is  used  in  the  foundry,  mixed  with  molding  sand  in 
different  proportions  according  to  the  class  of  castings  to  be 
made. 

For  castings  one-quarter  of  an  inch  thick  it  is  used  mixed  in 
the  proportions  of  one  part  of  seacoal  and  twelve  parts  of  sand, 
depending  somewhat  on  how  sharp  the  iron  is  to  be  poured, 
and  with  lesser  amounts  of  sand  to  one  part  of  seacoal  for 
the  heavier  castings. 

For  castings  one-eighth  of  an  inch  thick,  as  for  certain 
classes  of  cotton  machinery  and  in  the  teeth  of  fine  gears  which 
are  hard  to  free  from  sand  with  pickle,  it  is  mixed  in  the  propor- 
tion of  one  part  seacoal  to  twenty  parts  of  sand,  while  on  car- 
wheels  it  is  used  one  of  seacoal  to  nine  of  sand.  It  often  is 
used  in  front  of  a  gate  where  there  is  supposed  to  be  danger 
of  iron  cutting  the  mold  as  it  enters. 

One  part  of  seacoal  to  five  parts  coarse  molding  sand  is 
about  as  strong  as  it  can  be  used.  It  is  well  tore  member, 
when  using  strong  seacoal  facing  sand,  to  use  the  vent-wire 
freely,  as,  the  stronger  the  facing,  the  more  gas  there  is  to 
escape. 

In  mixing  seacoal  facing  for  green-sand  work,  the  sand 
should  be  used  as  dry  as  possible,  and  when  the  proper  propor- 
tion of  seacoal  has  been  added  to  the  sand,  it  should  be 
shoveled  over  in  order  to  mix  it  thoroughly,  and  then  riddled. 
If  flour  is  to  be  added  to  the  mixture  it  is  added  at  the  same 
time  as  the  seacoal.  The  mass  is  wet  down  and  turned  over  in 
order  to  mix  it,  and  is  tramped  to  force  the  component  parts 
together,  and  to  break  up  the  lumps.  It  is  next  passed  through 
a  No.  8  sieve.  For  some  of  the  larger  castings  a  little  flour  is 
added,  say,  one  part  flour  to  twenty- five  parts  sand  for  a  mold 
that  is  to  be  skin-dried,  and  one  of  flour  to  thirty- two  of  sand 
where  it  is  not  skin-dried,  this  usually  being  done  when  a 
poorer  grade  of  molding  sand  is  used  which  is  deficient  in  bond. 


23O  FOUNDRY    PRACTICE 

When  mixing  the  seacoal  and  sand  it  is  well  to  remember 
that  if  mixed  too  strong,  or  if  too  much  seacoal  is  used  in  pro- 
portion to  the  amount  of  sand,  the  casting  will  be  "veined" 
or  "mapped." 

Seacoal  is  not  used  generally  to  produce  an  especially 
smooth  surface  on  castings,  although,  if  a  little  lead  be  used 
with  seacoal  facing,  there  will  be  produced  a  fairly  smooth 
casting. 

Plumbago. — Among  the  many  facings  used  in  the  foundry 
to  give  the  castings  a  clean,  bright  surface,  and  to  prevent 
the  sand  from  burning  on  to  the  face  of  the  casting,  there  is 
no  greater  favorite  than  the  facing  known  as  plumbago;  silver 
lead  and  Ceylon  lead  stand  high.  There  are  large  quantities 
of  Ceylon  lead  used  in  the  manufacture  of  foundry  facings,  and 
the  richer  they  are  in  it,  the  better  the  results  obtained.  The 
pure  material  gives  the  smooth  surface  desired  in  machinery 
castings,  it  being  applied  after  the  mold  is  faced  with  the  sea- 
coal  facing. 

Ceylon  lead  or  graphite  is  "native  carbon  in  hexagonal 
crystals,  also  foliated  or  granular  masses,  of  black  color  and 
metallic  luster,  and  so  soft  as  to  leave  a  trace  on  paper."  It 
is  often  called  plumbago  or  black  lead.  Ceylon  graphite  of 
high  grade  for  facing  purposes  should  analyze  about  as  follows: 
moisture,  1.20  per  cent.;  alumina,  3.06  per  cent.;  silica,  16.14 
per  cent.;  oxide  of  iron,  5.90  per  cent.;  lime,  0.90  per  cent.; 
graphitic  carbon,  72.80  per  cent. 

The  bulk  of  Ceylon  graphite  imported  for  foundry  facings 
runs  between  50  to  60  per  cent  graphitic  carbon.  For  thin 
castings  the  lead  is  usually  placed  in  a  bag  which  is  shaken 
over  the  mold,  the  lead  passing  through  and  falling  lightly  on 
the  face  of  the  mold  until  enough  has  been  applied  to  give  the 
desired  result.  After  it  has  been  brushed  with  a  camel's-hair 
brush,  the  mold  is  blown  out  with  the  bellows  to  remove  any 
lead  not  adhering  to  the  face  of  the  mold. 

In  molds  for  very  thin  castings  the  lead  at  times  cannot  be 
brushed  on.  In  such  cases  a  little  charcoal  is  dusted  on  top  of 
the  mold  and  the  pattern  is  printed  back,  the  charcoal  keeping 


MOLDING    SANDS  23! 

the  lead  from  sticking  to.the  pattern  and  spoiling  the  face  of 
the  mold.  Or  it  may  be  dusted  on  and  blown  off  as  the  con- 
dition and  form  of  mold  may  require.  Thicker  castings, 
however,  require  the  aid  of  seacoal  facing.  With  such  molds, 
the  lead  is  sometimes  brushed  on  with  a  camel's-hair  brush, 
light,  quick  strokes  being  used.  Again,  on  the  heavier  cast- 
ings it  may  be  rubbed  on  with  the  hand  and  then  lightly 
brushed  off;  also  it  is  often  slicked  on  with  the  trowel  and 
slicker. 

For  blacking  dry-sand  molds  lead  is  sometimes  wet  with 
molasses  water,  and  brushed  on,  and  the  heavier  castings  are 
usually  blackened  with  a  mixture  made  to  the  consistency  of 
cream  and  laid  on  with  a  swab.  After  the  blacking  has  been 
allowed  to  set,  the  face  of  the  mold  is  slicked  all  over  with  tools, 
and  then  lightly  brushed  with  molasses  water  to  give  it  a 
finishing  smoothness.  It  is  also  used  in  the  same  way  for 
blacking  cores. 

On  loam  molds,  it  is  advisable  to  boil  and  add  a  little  com- 
mon starch  to  the  blacking  mixture,  and  to  slick  the  blacking 
green  on  the  face  of  the  mold.  The  starch  will  prevent  the 
blacking  from  flaking  off  in  thin  sheets.  Clay  water  is  some- 
times used  instead  of  starch. 

German  lead  is  sticky  on  green-sand  molds  when  used  alone 
and  requires  a  coating  of  charcoal  over  it  to  prevent  it  from 
adhering  to  the  tool.  It  is  largely  used  for  mixture  with 
other  blackings,  to  make  a  wet  blacking  for  dry-sand  and  loam 
molds.  It  will  peel  heavy  castings  when  used  properly. 

Mexican  and  Austrian  leads,  or  graphite,  are  used  by  many 
in  place  of  Ceylon  lead,  as  they  are  much  cheaper,  but  do  not 
work  as  nicely  on  the  heavier  class  of  castings,  or  give  them 
the  attractive  color  or  surface  that  Ceylon  lead  does.  They  do 
not  resist  heat  and  protect  the  mold  like  Ceylon  lead. 

Blackstone  and  Valley  Falls  lead,  also  called  Rhode  Island 
facing,  is  a  carbonaceous  mineral  which  is  neither  coal  nor  lead, 
but  when  ground  fine  and  applied  to  the  face  of  a  mold  is 
capable  of  protecting  it  from  the  intense  heat  of  the  molten 
metal.  It  is  naturally  sticky  and,  if  shaken  on  to  the  face  of  a 


232  FOUNDRY   PRACTICE 

mold  through  a  bag  and  slicked,  requires  a  coating  of  charcoal 
to  prevent  it  from  sticking  to  the  tools.  It  was,  and  is  still, 
used  to  some  extent  as  a  facing  for  stove-plate  molds,  by  being 
shaken  on  to  the  mold  through  a  bag,  after  which  a  coating  of 
charcoal  is  shaken  on  top  of  it  and  the  pattern  replaced.  This 
is  called  "printing  back  the  pattern."  It  is  also  used  with 
other  blackings  to  make  wet  blacking,  for  dry-sand  and  loam 
work. 

Lehigh  blacking  consists  of  Lehigh  coal  ground  fine  and 
is  used  to  mix  with  other  blackings  to  make  wet  blacking 
for  dry-sand  and  loam  work. 

Coke  blacking  is  coke  ground  fine  for  mixing  with  other 
blackings  for  making  wet  blacking. 

Charcoal  blacking  or  powdered  charcoal  is  used  on  green-sand 
molds  over  other  blackings  which  would  stick  to  tools.  It  is 
used  in  stove-plate  work  when  printing  back  to  prevent  other 
blackings  from  sticking  to  the  patterns.  It  may  be  used  as  a 
facing  for  dusting  on  very  light  work,  but  it  requires  something 
to  cause  it  to  adhere  to  the  face  of  the  mold.  For  this  reason 
it  is  used  in  place  of  parting  sand  at  times,  to  part  molds  in 
making  very  light  castings.  It  is  used,  too,  in  mixtures  of 
wet  blacking  to  keep  the  tools  from  sticking  to  the  blacking 
and  to  allow  the  blacking  to  be  slicked,  which  could  not  be 
done  if  charcoal  were  not  used. 

Talc  or  soapstone,  sometimes  called  white  plumbago,  is 
used  in  mixtures  of  blacking  for  cores  and  for  dry-sand  work. 
It  will  give  a  coating  capable  of  resisting  a  high  degree  of  heat, 
and  when  shaken  on  the  face  of  a  mold  after  the  mold  has  been 
given  a  coating  of  lead,  or  other  blacking,  the  iron  will  run 
on  it  farther  and  smoother  than  it  will  without  it.  In  this 
way  cold  shuts  may  be  avoided.  Castings  made  in  molds 
in  which  it  has  been  used  show  something  of  a  cream  color 
when  coming  from  the  sand,  instead  of  the  handsome  blue 
shade  shown  when  Ceylon  lead  is  used. 

Gashouse  carbon  facing  is  carbon  taken  from  the  gas  retorts 
and  ground.  It  is  one  of  the  best  facings  for  mixing  with 
others  for  wet  blacking  for  cores,  dry-sand,  and  loam  molds. 


MOLDING    SANDS  233 

Fire  sand  is  a  highly  refractory  silica  sand  used  in  making 
molds  for  iron  and  steel.  In  the  foundry  it  is  used  to  mix  with 
coarse  molding  sand  to  form  mixtures  for  making  dry-sand  and 
loam  work  and  to  make  mixtures  for  facing  molds  of  cylinders 
for  steam-  and  gas-engines.  Of  the  larger  sizes,  hydraulic  and 
pump  cylinders,  rolls  and  castings  requiring  to  be  sound  and 
clean,  or  to  have  a  positive  thickness  of  walls  or  where  on  ac- 
count of  the  weight  or  for  some  special  reason  it  may  be  con- 
sidered safer  to  make  the  casting  in  dry  rather  than  in  green 
sand. 

As  a  base  to  work  from  there  may  be  used  seven  parts 
good  coarse  molding  sand  and  seven  parts  coarse  New  Jersey 
fire  sand  mixed,  to  which  is  added  one  part  flour  and  after  the 
whole  has  been  thoroughly  mixed  it  should  be  wet  with  mo- 
lasses water  mixed  in  the  proportion  of  one  part  molasses  to 
fourteen  or  sixteen  parts  water. 

The  mixture  is  varied  according  to  the  quality  and  grade 
of  sands  and  flour  for  the  grade  of  work.  This  sand  is  also 
mixed  with  other  sands  for  making  large  cores  where  the  cores 
are  to  be  subjected  to  intense  heat  from  large  bodies  of  metal. 
It  is  also  used  for  making  the  hearth  for  reverberatory  fur- 
naces, being  wet  with  claywash  or  mixed  with  ground  clay 
dry,  and  then  wet.  It  is  also  valuable  for  forming  mixtures 
for  daubing  large  ladles,  or  in  lining  large  cupolas. 


CHAPTER  XXIII 

IRON  AND  ITS  COMPOSITION 

IRON,  the  metal  most  generally  used  in  the  foundry,  is  one 
of  the  chemical  elements.  The  iron  of  commerce,  however, 
is  not  pure  metal,  but  is  a  compound  of  iron  with  various 
metalloids  such  as  carbon,  silicon,  phosphorus,  sulphur,  man- 
ganese, etc.  Each  of  these  exercises  an  important  influence 
on  the  structure  of  the  iron,  the  latter  principally  through  their 
action  on  the  carbon,  which  is,  without  doubt,  the  most  im- 
portant element  entering  into  the  iron.  The  percentage  of 
carbon  in  the  iron  determines  its  grade  and  also  whether  it 
comes  under  the  classification  of  iron  or  steel.  These  points 
will  be  discussed  in  more  detail  later. 

The  iron  of  commerce  when  examined  under  the  microscope 
has  a  structure  closely  allied  to  granite  in  appearance.  It  is 
composed  of  two  definite  substances,  known  to  the  metal- 
lurgists respectively  as  ferrite  and  cementite.  The  former  is 
pure  metallic  iron  and  is  soft,  weak,  and  very  ductile.  The 
latter  is  a  chemical  compound  of  iron  and  carbon,  is  harder 
than  glass  and  very  brittle.  It,  however,  has  great  strength 
to  resist  gradually  applied  pressure.  The  relative  proportion 
of  ferrite  and  cementite  in  any  given  iron  determines  its  grade. 

Carbon. — The  total  amount  of  carbon  in  cast-iron  ranges 
from  3  to  4  per  cent.  It  exists  in  the  iron  in  three  states, 
namely :  combined  carbon  which  is  the  carbon  in  the  carbide 
of  iron  forming  the  cementite;  free  carbon,  also  known  as 
graphitic  carbon,  which  exists  in  the  form  of  small  flakes  of 
pure  carbon  entangled  in  the  crystals  of  ferrite  and  cementite; 
and  tempering  graphite  carbon  into  which  combined  carbon  is 
gradually  changed  by  the  prolonged  application  of  heat.  This 
last  is  relatively  unimportant  compared  to  the  other  two. 

The  combined  carbon  has  the  effect  of  increasing  the  hard-  - 
234 


IRON  AND   ITS   COMPOSITION  235 

ness,  shrinkage,  and  brittleness  of  cast-iron.  The  strength  of 
the  iron  increases  with  the  amount  of  combined  carbon  up  to 
about  i  per  cent  of  the  latter.  Above  i  per  cent,  combined 
carbon  tends  to  decrease  the  strength  of  the  metal. 

The  graphitic  carbon  tends  to  soften  and  weaken  the  iron 
if  present  in  quantities  of  over  3  per  cent.  If  the  iron  contains 
i  per  cent  or  more  of  combined  carbon,  being  at  the  same  time 
low  in  graphitic  carbon,  any  additions  of  the  latter  will  in- 
crease the  strength  of  the  casting.  The  amount  of  graphitic 
carbon  in  a  casting  is  increased  with  the  size  of  the  casting, 
and  it  is  also  increased  when  the  casting  is  held  a  long  time  in 
the  mold  at  high  temperature;  in  other  words,  when  it  is 
cooled  slowly.  This  is  due  to  the  action  of  the  combined 
carbon  changing  to  temper  graphite  as  explained  above. 

Silicon. — The  tendency  of  silicon  in  cast-iron  is  to  soften 
the  casting.  It  acts  by  changing  combined  carbon  into 
graphitic  carbon  and  also  by  counteracting  the  effect  of  any 
sulphur  which  may  be  present  and  which  exercises  a  harden- 
ing effect  upon  the  iron.  The  silicon  also  may  act  to  increase 
the  strength  of  the  iron  when  the  latter  is  high  in  combined 
carbon,  as  it  tends  to  reduce  brittleness.  If,  however,  the 
addition  of  silicon  is  such  as  to  reduce  the  combined  carbon  to 
below  i  per  cent  it  will  seriously  weaken  the  iron.  If  present 
in  quantities  over  3.5  per  cent  it  changes  the  character  of  the 
iron  entirely,  the  iron  becoming  silvery  in  color  instead  of  gray 
and  also  becoming  brittle  and  weak.  Manganese  present  in 
the  iron  will,  like  sulphur,  react  with  the  silicon  and  decrease 
the  effect  of  the  latter  on  the  iron. 

Sulphur. — Sulphur  present  in  the  iron  reacts  with  the 
carbon  present  to  form  combined  carbon  and  thereby  increases 
the  hardness,  brittleness,  and  shrinkage  of  the  casting.  In  ad- 
dition to  r'ts  action  on  the  carbon  it  also  has  in  itself  a  weaken- 
ing effect  on  the  iron.  On  account  of  its  effect  on  the  shrink- 
age, patterns  which  are  made  for  use  with  iron  high  in  sulphur 
must  have  a  greater  shrinkage  allowance  than  the  usual  one- 
eighth  inch  per  foot,  otherwise  the  casting  will  be  smaller  than 
desired.  The  sulphur  should  never  be  permitted  to  increase 


236  FOUNDRY    PRACTICE 

beyond  o.i  per  cent,  as  any  excess  of  this  amount  will  render 
the  iron  brittle  and  weak  unless  other  elements  are  present  in 
sufficient  quantity  to  counteract  it.  The  iron  will  be  danger- 
ously brittle  even  with  such  a  low  quantity  as  0.06  per  cent 
sulphur  if  the  amount  of  silicon  present  is  less  than  I  per  cent. 

Phosphorus. — The  general  effect  of  phosphorus  is  to  in- 
crease the  fluidity  of  the  iron.  In  small  quantities,  say  below 
0.7  per  cent,  it  has  but  little  effect  on  the  strength  of  the  iron, 
but  if  present  in  quantities  of  I  per  cent  or  more  the  effect  is 
decidedly  weakening.  Like  silicon  it  acts  to  increase  the  soft- 
ness of  the  iron  and  also  to  decrease  the  shrinkage.  On  account 
of  its  increasing  the  fluidity  of  the  iron,  it  is  a  desirable  element 
when  thin  castings  such  as  stove  plates  are  to  be  made,  as  the 
iron  will  flow  freely  to  all  parts  of  the  mold  before  cooling.  It 
is  also  valuable  in  ornamental  castings  of  thin  section  which 
have  on  their  surface  fine  lines  and  sharp  projections.  The 
iron  containing  phosphorus  will  flow  freely  into  these  lines 
and  projections  and  reproduce  the  pattern  perfectly.  / 

Manganese. — Manganese  when  present  in  quantities  of 
2  per  cent  or  more  increases  the  hardness  of  the  iron.  When 
present  in  small  quantities,  say  0.5.  per  cent  or  less,  it  tends  to 
counteract  the  effect  of  the  sulphur  present  and  thus  acts  as 
a  softener.  In  quantities  of  from  0.5  per  cent  to  2.0  per  cent 
it  changes  graphitic  carbon  to  combined  carbon  and  thus  acts 
as  a  hardener.  A  peculiar  property  of  manganese,  and  one 
wherein  it  differs  from  most  of  the  other  constituents  of  iron, 
is  that  it  will  combine  with  iron  chemically  in  almost  all  pro- 
portions. In  quantities  of  10  to  30  per  cent  in  the  iron  it 
forms  spiegeleisen  and  when  present  in  quantities  of  over  50 
per  cent  the  alloy  is  known  as  ferro-manganese.  These  alloys 
are  used  as  additions  to  iron  and  steel  in  the  ladle  after  they 
have  been  melted  in  the  cupola  or  other  furnace  to  make  up 
deficiencies  in  the  metal  and  to  act  as  softeners  or  to  toughen 
the  metal  as  the  case  may  require.  Manganese  also  acts  to 
increase  shrinkage.  While  ordinary  pig  iron  usually  contains 
not  over  4  per  cent  of  carbon,  this  quantity  can  be  increased 
in  the  presence  of  manganese,  which  increases  the  solubility  of 


IRON  AND   ITS   COMPOSITION  237 

carbon  in  iron.  The  property  of  manganese  to  toughen  and 
harden  cast-iron  is  taken  advantage  of  in  the  casting  of  chilled 
rolls,  on  which  a  hard  surface  is  desired.  It  is  added  in  quan- 
tities of  about  i  per  cent.  It  must  not  be  permitted  to  exceed 
0.4  per  cent  if  softness  is  required  in  the  finished  casting. 
Another  effect  of  manganese  is  to  decrease  the  magnetism  of 
iron  and  it  must  therefore  be  avoided  in  castings  for  electrical 
machinery,  as  iron  with  25  per  cent  manganese  is  totally  de- 
void of  magnetism. 

Miscellaneous  Impurities. — Other  metals  often  encoun- 
tered in  iron  are  as  follows:  Aluminum  in  quantities  of  from 
0.2  to  i  .o  per  cent  will  increase  the  softness  and  strength  of 
white  iron.  Added  to  gray  iron  it  softens  and  weakens  it. 
Vanadium,  in  quantities  of  0.15  per  cent,  will  increase  the 
strength  of  iron,  acting  as  deoxidizer  and  also  alloying  with  the 
iron.  Titanium,  when  added  in  quantities  of  2  to  3  per  cent 
of  a  titanium-iron  alloy  containing  10  per  cent  titanium,  will 
increase  the  strength  of  the  iron  from  20  to  30  per  cent.  Its 
action  is  to  combine  with  any  oxygen  or  nitrogen  present  in 
the  metal  and  thus  purify  it.  The  titanium  oxide  or  nitride 
passes  off  and  no  titanium  remains  in  the  metal.  After  the 
metal  has  been  totally  deoxidized,  further  additions  of  tita- 
nium have  no  effect.  Aluminum,  vanadium,  and  titanium  are 
all  added  to  the  iron  in  the  ladle  after  melting,  in  the  form  of 
alloys  of  these  metals  with  iron.  Copper  when  present  in 
quantities  of  o.i  to  i.o  per  cent  closes  the  grain  of  cast-iron, 
but  has  no  particular  effect  as  regards  brittleness. 

GRADING  OF  PIG  IRON 

Up  to  quite  recent  times,  pig  iron  was  graded  by  the  foun- 
drymen  and  blast-furnace  operators  largely  according  to  the 
appearance  of  the  fracture  obtained  when  a  pig  was  broken. 
As  the  appearance  of  the  fracture  depends  on  the  relative 
quantities  of  graphitic  and  combined  carbon  present,  this 
method  gave  a  fairly  close  approximation  to  the  quality  of  the 
iron.  In  more  recent  years,  however,  grading  by  fracture  has 


FOUNDRY   PRACTICE 


been  largely  superseded  by  the  method  of  grading  by  analysis. 
The  designations  of  pig  iron  according  to  grade  vary  in  dif- 
ferent sections  of  the  country.  Thus  in  Pennsylvania  and 
eastern  parts  of  the  United  States  grades  are  known  as  Nos. 
i  and  2  Foundry,  Gray  Forge  No.  3,  Mottled  No.  4,  White 
No.  5.  Intermediate  grades  are  designated  by  the  addition 
of  the  letter  X  to  the  grade  of  the  higher  number.  Thus  an 
intermediate  grade  between  Nos.  2  and  3  would  be  known  as 
No.  3X.  The  following  table  from  Kent's  "Mechanical 
Engineers'  Pocket-Book,"  eighth  edition,  page  414,  gives  the 
analyses  of  the  five  standard  grades  of  northern  foundry  and 
mill  pig  iron : 

TABLE  V. — ANALYSES  OF  FOUNDRY  IRONS 


No.  i 

No.  2 

No.  3 

No.  4 

No.  48 

No.  S 

Iron 

Per  Cent 

92  37 

Per  Cent 
Q2    31 

Per  Cent 
Q4.  66 

Per  Cent 
Q4.  4.8 

Per  Cent 
Q4.  08 

Per  Cent 
94  68 

Graphitic  carbon  
Combined  carbon.  .  .  . 
Silicon  
Phosphorus  

3.52 
0.13 

2-44 
i  .25 

2.99 

0-37 

2.52 
I.  08 

2.50 
1-52 
0.72 
0.26 

2.  02 
I.98 
0.56 

o  19 

2.02 

1-43 
0.92 

o  04 

3-83 
0.41 

o  04 

Sulphur 

o  02 

o  02 

o  08 

o  04. 

o  02 

Manganese 

o  28 

o  72 

°  34 

o  67 

2   O2 

o  98 

The  characteristics  of  the  above  irons  are  given  in  the  same 
work  as  follows: 

No.  I  Gray. — A  large,  dark,  open-grained  iron,  softest  of 
all  the  numbers  and  used  exclusively  in  the  foundry.  Tensile 
strength  low.  Elastic  limit  low,  fracture  rough,  turns  soft 
and  tough. 

No.  2  Gray. — A  mixed,  large  and  small,  dark  grain,  harder 
than  No.  I,  and  used  exclusively  in  the  foundry.  Tensile 
strength  and  elastic  limit  higher  than  No.  i.  Fracture  less 
rough  than  No.  i.  Turns  harder,  less  tough,  and  more  brittle 
than  No.  i. 

No.  3  Gray. — Small,  gray,  close  grain,  harder  than  No.  2, 
used  either  in  the  rolling  mill  or  foundry.  Tensile  strength 


IRON  AND   ITS   COMPOSITION  239 

and  elastic  limit  higher  than  No.  2.  Turns  less  hard,  less 
tough,  and  more  brittle  than  No.  2. 

No.  4  Mottled. — White  background  dotted  closely  with 
small  black  spots  of  graphitic  carbon.  Little  or  no  grain. 
Used  exclusively  in  the  rolling  mill.  Tensile  strength  and 
elastic  limit  lower  than  No.  3.  Turns  with  difficulty,  less 
tough  and  more  brittle  than  No.  3.  The  manganese  in  the  No. 
46  pig  iron  replaces  part  of  the  combined  carbon,  making  the 
iron  harder  and  closing  the  grain,  notwithstanding  the  lower 
combined  carbon. 

No.  5  White. — Smooth,  white  fracture,  no  grain.  Used 
exclusively  in  the  rolling  mill.  Tensile  strength  and  elastic 
limit  lower  than  No.  4.  Too  hard  to  turn  and  more  brittle 
than  No.  4. 

For  making  chilled  castings  a  special  grade  of  iron  is  re- 
quired, one  which  has  a  gray  fracture  when  cooled  slowly,  but 
which  when  cast  against  a  chill  will  show  white  iron  for  a  cer- 
tain depth  on  the  side  which  was  rapidly  cooled  by  reason 
of  its  contact  with  the  iron  chill.  See  the  analyses  of  chilled 
castings,  Table  VIII,  pages  242-3. 

SPECIFICATIONS  FOR  FOUNDRY  PIG  IRON 

In  May,  1909,  the  American  Foundrymen's  Association 
adopted  standard  specifications  for  foundry  pig  iron  and  rec- 
ommended that  all  pig  iron  for  foundry  use  be  bought  by 
analysis.  It  recommended  sampling  each  carload  of  iron, 
taking  therefrom  one-half  of  a  sand-cast  pig  or  one  machine- 
cast  pig  for  every  four  tons  in  the  car.  Drillings  should  be 
taken  fron  these  pigs  to  represent  as  nearly  as  possible  the 
composition  of  the  pig  as  cast  and  an  equal  quantity  of  the 
drillings  from  each  pig  should  be  mixed  to  form  the  sample 
for  analysis.  When  the  elements  are  specified,  the  following 
percentages  and  variations  are  to  be  used.  Opposite  each 
percentage  of  the  different  elements  a  syllable  has  been 
affixed  so  that  buyers  by  combining  these  syllables  can  form  a 
code  word  for  telegraphic  use. 


240 


FOUNDRY  PRACTICE 
TABLE  VI 


SILICON 

SULPHUR 

TOTAL  CARBON 

MANGANESE 

PHOSPHORUS 

Per  Cent 

Code 

(Max.) 

Code 

(Min.) 

Code 

Per  Cent 

Code 

Per  Cent 

Code 

0.04 

Sa 

3.00 

Ca 

O.20 

Ma 

O.2O 

Pa 

1.  00 

La 

0.05 

Se 

3-20 

Ce 

0.40 

Me 

0.40 

Pe 

1.50 

Le 

0.06 

Si 

3-40 

Ci 

0.60 

Mi 

0.60 

Pi 

2.OO 

Li 

O.O/ 

So 

3-60 

Co 

0.80 

Mo 

0.80 

Po 

2.50 

Lo 

0.08 

Su 

3-8o 

Cu 

1.  00 

Mu 

1.  00 

Pu 

3-oo 

Lu 

O.OQ 

Sy 

1-25 

My 

1-25 

Py 

0.10 

Sh 

1.50 

Mh 

1.50 

Ph 

Percentages  of  any  element  specified  one-half  way  between 
the  above  are  designated  by  the  addition  of  the  letter  x  to  the 
next  lower  symbol.  Thus  Lex  means  1.75  silicon.  The 
allowed  variations  are  silicon  0.25,  phosphorus  0.20,  manganese 
0.20.  The  percentages  of  phosphorus  and  manganese  may  be 
used  as  maximum  or  minimum  figures  when  so  specified.  An 
example  of  the  use  of  the  above  code  is  as  follows :  Li-si-pa-ma 
represents  an  iron  of  the  following  analysis — Silicon  2.00, 
sulphur  0.06,  phosphorus  0.20,  manganese  0.20.  For  market 
quotations,  an  iron  of  2  per  cent  silicon  with  a  variation  of 
0.25  per  cent  either  way  and  maximum  sulphur  content  of 
0.05  is  taken  as  the  base  and  the  following  table  may  then  be 

-    TABLE  VII 


Sul- 
phur 

Silicon 
2.25 

B+2C 

I.OO 

B-3C 

3.25 

B+6C 

3.00 
B+SC 

2-75 
B+4C 

2.50 
B+3C 

2.OO 

B  +  C 

1-75 
B 

1.50 
B-iC 

1-25 
B-2C 

0.04 

0.05 

B+sC 

B+4C 

B+3C 

B+2C 

B+iC 

B 

B-iC 

B-2C 

B-3C 

B-4C 

0.06 

B+4C 

B+3C 

B+2C 

B+iC 

B 

B-iC 

B-2C 

B-3C 

B-4C 

B-5C 

0.07 

B+3C 

B+2C 

B+iC 

B 

B-iC 

B-2C 

B-3C 

B-4C 

B-5C 

B-6C 

0.08 

B+2C 

B+iC 

B 

B-iC 

B-2C 

B-3C 

B-4C 

B-sC 

B-6C 

B-7C 

0.05 

B+iC 

B 

B-iC 

B-2C 

B-3C 

B-4C 

B-sC 

B-6C 

B-7C 

B-8C 

O.IO 

B 

B-iC 

B-2C 

B-3C 

B-4C 

B-sC 

B-6C 

B-7C 

B-8C 

B-9C 

IRON   AND    ITS    COMPOSITION  24! 

filled  out  as  part  of  a  contract.  In  this  table  B  or  base 
represents  the  agreed  price  for  a  pig  of  2  per  cent  silicon  and 
of  lower  sulphur  content  than  0.05.  C  is  a  constant  differen- 
tial to  be  determined  at  the  time  the  contract  is  made. 

ANALYSES  OF  CASTINGS 

A  committee  of  the  American  Society  for  Testing  Materials 
in  1908  recommended  that  the  sulphur  in  light  gray-iron 
castings  be  not  allowed  to  exceed  0.08  per  cent;  in  medium 
castings  not  over  o.io  per  cent;  in  heavy  castings  not  over 
0.12  per  cent.  A  light  casting  is  one  which  has  no  section  over 
one-half  inch  thick  and  a  heavy  casting  has  no  section  less 
than  two  inches  thick.  The  same  society  in  1905  specified 
for  metal  in  cast-iron  pipe  four  grades  of  pig  iron  as  follows: 
No.  I,  silicon  2.75,  sulphur  0.035;  No.  2,  silicon  2.25,  sulphur 
0.045;  No.  3,  silicon  1.75,  sulphur  0.055;  No.  4,  silicon  1.25, 
sulphur  0.065.  A  variation  of  10  per  cent  either  way  in  the 
silicon  is  permitted  and  of  o.oi  per  cent  in  the  sulphur  above 
the  standard  is  allowed. 

In  June,  1910,  the  American  Foundrymen's  Association 
published  a  report  by  Dr.  John  Jermain  Porter,  showing 
tentative  standards  or  probable  best  analyses  of  a  large 
variety  of  iron  castings.  This  report  was  abridged  in  tabular 
form  as  reproduced  below  in  Industrial  Engineering  in  August, 
1910.  The  definitions  of  light  and  heavy  castings  conform 
to  those  given  in  the  above  paragraph.  The  most  desirable 
percentage  of  silicon  depends  largely  on  the  exact  thickness  of 
the  casting  and  the  practice  followed  in  shaking  out.  The 
effect  of  purifying  alloys  and  the  use  of  steel  scrap  were  not 
considered  in  compiling  the  report.  In  many  cases  a  wide 
range  of  compositions  is  permissible  and  compatible  with  the 
best  results,  and  in  such  cases  the  question  of  cost  will  be  the 
first  element  to  be  considered.  The  sources  of  information  in 
compiling  this  table  were  published  works,  replies  to  inquiries 
sent  to  members  of  the  association,  and  private  notes  of 
Dr.  Porter. 
16 


242 


FOUNDRY   PRACTICE 


TABLE  VIII. — ANALYSES  OF  CASTINGS 


"Class  of  Casting 

Si 
Per  Cent 

s 

Per  Cent 

p 

Per  Cent 

Mn 
Per  Cent 

C 

(Comb.) 
Per  Cent 

c 

(Total) 
Per  Cent 

Acid-resisting    castings    (stills, 

1.00-2.00 

2.00-2.50 

0.05-* 
0.06-0.08 

0.40-* 
0.60-0.80 

1.00-1.50 
0.60-0.80 



3.00-3.50 

Agricultural    machinery,    ordi- 
nary   
Agricultural    machinery,    very 
thin 

Annealing  boxes,  etc  
Automobile  castings  
Balls  for  ball  mills  
Boiler  castings  
Car  castings,  gray  iron  
Chilled  castings  
Chills 

.40-1.60 
•75-2.25 
.00-1.25 
.00-2.50 
.50-2.25 
•7S-I.2S 

0.06- 
0.08- 
0.08- 
'0.06- 
0.08- 
0.08-0.10 

O.2O- 
O.40-O.50 
O.20- 
O.2O- 

0.40-0.60 
O.2O-0.4 

0.60-1.00 
0.60-0.80 
0.60-1.00 
0.60-1.00 
0.60-1.00 
0.80-1.20 

:::::::: 

.80-1.00 

0.08-0.10 

O.2O-O.4 

0.80-1  20 

Cutting  tools,  chilled  
Cylinders: 
Air  and  ammonia  

.00-1.25 

.00-1.75 
.75-2.00 
.00-1.75 

0.08- 

0.09- 
0.08- 
0.08- 

O.2O-O.4 

O.30-0.5 
0.4O-O.5 
O.20-O.4O 

0.60-0.80 

0.70-0.90 
0.60-0.80 
0.70-0.90 

O.'ss'-o'.os 

3.00-3.30 
3.00-3.25 
3.00-3.30 

low 
low     • 

low 

Hydraulic,  medium  
Locomotive  
Steam-engine,  heavy  
Steam-engine,  medium  
Dies,  drop-hammer  
Diamond  polishing  wheelsf.  .  .  . 
Electrical    machinery    (frames, 
bases,  spiders)  ,  large  
Electrical  machinery,  small.  .  . 
Engine  castings: 

.20-1.60 
.00-1.50 
.00-1.25 
.25-1.75 
.25-1.50 
2.70 

.00-2.50 
.50-3.00 

0.09- 
0.08-0.10 

O.IO- 

0.09- 
0.07- 
0.063 

0.08- 

0.08- 

0.30-0.50 
O.3O-O.50 
O.20-O.4O 
0.30-0.50 
0.20- 
O.3O 

O.5O-O.8O 
0.50-0.80 

0.70-0.90 
0.80-1.00 
0.80-1.00 
0.70-0.90 
0.60-0.80 
0.44 

0.30-0.40 
0.30-0.40 

"i.o'o" 

0.20-0.30 
0.20-0.30 

low 
2.97 

low 
low 

Fly-wheels  
Fly-wheels,  automobile  
Frames  
Pillow  blocks  

.50-2.25 
.25-2.50 
.25-2.00 
.50-1.75 

0.08- 
0.07- 
0.09- 
0.08- 

0.40-0.60 
O.4O-O.5O 
O.3O-O.5O 
O.40-O.5O 

0.50-0.70 
0.50-0.70 
0.60-1.00 
0.60-0.80 

Piston  rings  
Fire  pots  and  furnace  castings. 
Grate  bars  
Grinding     machinery,     chilled 

.50-2.00 
.00-2.50 
.00-2.50 

•50-0.75 
.00-1.25 
.00-1.25 

0.08- 
0.06- 
0.06- 

0.15-0.20 
0.06- 
0.06- 

0.08- 

0.30-0.50 
O.20- 
O.2O- 

0.20-0.40 
O.2O-O.30 
O.2O-O.30 

0.40-0.60 
0.60-1.00 
0.60-1.00 

1.50-2.00 
0.80-1.00 

0.30- 

low 
low 
low 

Gun-carriages  
Gun  iron  
Hardware,,  (light)    and    hollow 

0.80-1.00 

low 

low 

Heat-resistant  iron  (retorts)  .  .  . 
Ingot  molds  and  stools  
Locomotive  castings,  heavy.  .  . 
Locomotive  castings,  light.  .  .  . 
Machinery  castings,  heavy  .... 
Machinery  castings,  medium  .  . 
•  Machinery  castings,  light  
Friction  clutches  
Gears,  heavy  
Gears,  medium  
Gears,  small  
Pulleys,  heavy  
Pulleys,  light  
Shaft  collars  and  couplings  .  . 
Shaft  hangers  
Ornamental  work  
Permanent  molds  
Permanent  mold  castings  

.25-2.50 
.25-1.50 
.25-1.50 
.50-2.00 
.00-1.50 
.50-2.00 
.00-2.50 
.75-2.00 
.00-1.50 
.50-2.00 
.00-2.50 
.75-2.25 
.25-2.75 
.75-2.00 
.50-2.00 

.25-2.75 
.00-2.25 
.50-3.00 

0.06- 
0.06- 
0.08- 
0.08- 

O.IO- 
0.00- 

0.08- 
0.08-0.10 
0.80-0.10 

0.00- 

0.08- 
0.09- 
0.08- 
0.08- 
0.08- 
0.08- 
0.07- 
0.06- 

O.2O- 
O.2O- 
0.30-0.50 
O.4O-0.6O 
O.3O-O.5O 
0.40-0.60 
O.5O-O.7O 
O.3O- 
0.30-0.50 
0.40-0.60 
O.5O-O.7O 
O.5O-O.7O 
0.60-0.80 
O.4O-O.5O 
0.40-0.50 
O.6O-I.OO 
0.20-0.40 

0.60-1.00 
0.60-1.00 
0.70-0.90 
0.60-0.80 
0.80-1.00 
0.60-0.80 
0.50-0.70 
0.50-0.70 
0.80-1.00 
0.70-0.90 
0.60-0.80 
0.60-0.80 
0.50-0.70 
0.60-0.80 
0.60-0.80 
0.50-0.70 
0.60-1.00 
0.40- 

0.30- 

low 

'  '  low  '  ' 

:::::::: 

'  '  low  '  ' 

low 



*  Affixed  hyphens  indicate  that  the  percentages  present  should  be  under  those  given. 


IRON   AND   ITS   COMPOSITION 
TABLE  VIII. — ANALYSES  OF  CASTINGS — Continued 


243 


Class  of  Casting 

Si 
Per  Cent 

S 
Per  Cent 

P 

Per  Cent 

Mn 
Per  Cent 

C 

(Comb.) 
Per  Cent 

(ToteO 

Per  Cent 

Piano  plates  
Pipe 

.00-2.25 
.50-2.00 
•7S-2.SO 

•50-1.75 
.75-1.25 

0.07- 

O.IO- 

0.08- 

0.08- 
0.08- 

0.40-0.60 
.50-0.80 
.50-0.80 

.20-0.40 
.20-0.30 

0.60-0.80 
0.60-0.80 
0.60-0.80 

0.70-0.90 
0.80-1.00 

........ 

Pipe  fittings  
Pipe    fittings    for    superheated 
steam  lines  
Plow  points,  chilled  

low 

Propeller  wheels  
Pv.mps,  hand  

.00-1.75 
.00-2.25 
.00-2.25 
.50-2.25 

.00-1.25 

.60-0.80 
0.75 
.00-2.30 
.75-2.00 
.75-2.25 
.25-2.75 
•  25-1.75 

O.IO- 

0.08- 
0.08- 
0.08- 

0.08- 
0.06-0.08 
0.03 
0.08- 
0.07- 
0.09- 
0.08- 
0.09- 

20-0.40  0.60-1.00 
60-0.80  0.50-0.70 
60-0.80  0.50-0.70 
40-0  .60  o  .60-0  .80 

20-0.300.  80-1.00 
20-0.40  i.  oo-i.  20 
0.25           0.66 
60-1.000.  50-0.  70 
0.30-      0.70-0.90 
50-0.  80  p.  60-0.  80 
60-0.90(0.60-0.80 
20-0.40(0.80-1  .00 

0.50-0.60 

low 

Railroad  castings  
Rolling  mill  machinery: 
Housings  
Rolls,  chilled  
Rolls,  unchilled  (sand-cast)t 
Scales  
Slag  car  castings  
Soil  pipe  and  fittings  
Stove  plate  
Valves,  large  

low 
3-00-3.25 
4.10 

1.20 

'  '  low  '  ' 

Water  heaters  
Wheels,  large  
Wheels,  small.  

.00-2.25 
.50-2.00 
.75-2.00 
.50-0.90 

0.08- 
0.09- 
0.08- 
0.15-0.25 

30-0.50 
30-0.40 
40-0.50 
20-0.70 

0.60-0.80 
0.60-0.80 
0.50-0.70 
0.17-0.50 

2.90 

2.50 

t  But  one  or  two  analyses  available — no  suggestion  made. 

Mr.  W.  J.  Keep  in  the  Trans.  A.  S.  M.  E.,  Vol.  XXIX, 
writes  as  follows  regarding  the  analyses  of  iron  for  various 
classes  of  service : 

Hard  Iron  for  Heavy  Work.— Castings  for  compressor 
cylinder-valves,  high-pressure  work,  etc.  Chemical  composi- 
tion: Silicon  i. 20  to  1.50,  sulphur  under  0.09  per  cent,  phos- 
phorus 0.35  to  0.60  per  cent,  manganese  0.50  to  0.80  per  cent. 

Medium  Iron  for  General  Work. — Castings  for  low- 
pressure  cylinders,  gears,  pinions,  etc.  Chemical  composi- 
tion: Silicon  1.50  to  2.00  per  cent,  sulphur  under  0.08  per  cent, 
phosphorus  0.35  to  0.60  per  cent,  manganese  0.50  to  0.80  per 
cent. 

Soft  Iron. — For  general  car  and  railway  castings,  pulleys, 
small  castings,  and  agricultural  work.  Chemical  composition: 
Silicon  2. 20  to  2.80  per  cent  (with  less,  the  castings  are  hard, 
and  with  more  they  are  too  weak).  For  large  castings,  2.40 
per  cent  is  a  good  average.  Sulphur  under  .085  per  cent, 
phosphorus,  under  0.70,  manganese  under  0.70  per  cent. 


244 


FOUNDRY    PRACTICE 


Iron  for  Frictional  Wear. — Castings  for  brake  shoes, 
friction  clutches,  etc.  Chemical  composition:  Silicon  2.00  to 
2.50  per  cent,  sulphur  under  0.15  per  cent,  phosphorus  under 
0.70  per  cent,  manganese  under  0.70  per  cent.  The  addition 
of  spiegeleisen  increases  hardness. 

The  method  of  calculating  the  mixtures  of  the  various 
brands  of  pig  iron  available  for  cupola  charges  to  obtain  the 
analyses  as  given  in  the  above  notes  and  table  will  be  explained 
in  Chapter  XXIV. 

SHRINKAGE  OF  CAST-IRON 

The  common  allowance  for  shrinkage  of  cast-iron  in  cooling 
from  the  liquid  to  the  solid  state  is  one-eighth  inch  per  foot. 
As  has  been  shown  above,  however,  the  percentage  of  the 
various  elements  alloyed  with  the  iron  has  an  important  effect 
on  the  shrinkage.  Mr.  Keep  says:  "The  measure  of  shrinkage 
is  practically  equivalent  to  a  chemical  analysis  of  the  silicon. 
It  tells  whether  more  or  less  silicon  is  needed  to  bring  the  qual- 
ity of  the  casting  to  an  accepted  standard  of  excellence."  Mr. 
Keep  published  in  the  Trans.  A.  S.  M.  E.  the  following 
table  showing  the  variation  in  shrinkage  with  the  size  of  bar 
on  which  his  experiments  were  made  and  with  the  variation 
in  the  silicon  contents  of  the  iron.  See  also  the  Appendix, 
page  317. 

TABLE   IX.— SHRINKAGE  OF  CAST-IRON 


SILICON 


SIZE  OF  SQUARE  BARS 
Shrinkage,  Inch,  per  Foot 


Per  Cent 

y3  inch 

i  inch 

2  inch 

3  inch 

4  inch 

I  .OO 

0.178 

0.158 

0.129 

O.  112 

O.IO2 

1.50 

0.166 

0.145 

O.II6 

0.099 

0.088 

2.00 

0-154 

0-133 

0.104 

0.086 

0.074 

2.50 

0.142 

O.  121 

0.091 

0.072 

0.060 

3.00 

0.130 

0.109 

0.078 

0.058 

0.046 

3-50 

O.II8 

0.097 

0.065 

0.045 

0.032 

CHAPTER  XXIV 

THE  CUPOLA  AND  ITS  OPERATION 

FOR  melting  iron  for  foundry  use  two  types  of  furnaces  are 
commonly  used,  the  cupola  and  reverberatory  or  "air"  furnace. 
Of  these  the  cupola  is  the  most  widely  used,  although  the 
reverberatory  furnace  is  becoming  very  popular  for  certain 
classes  of  work.  There  are  many  different  cupolas  on  the 
market  which  vary  only  in  details  of  design.  In  principle 
they  are  all  alike.  A  typical  cupola  is  shown  in  Fig.  140.  As 
will  be  observed  it  is  a  straight  shaft  furnace  open  at  the  top 
and  bottom,  lined  with  fire-brick,  provided  with  a  door  at  about 
the  middle  of  its  height  through  which  the  charge  is  introduced 
and  with  tuyeres  near  the  bottom  through  which  air  is  blown  to 
consume  the  fuel  which  is  charged  to  melt  the  iron.  The  open- 
ing at  the  bottom  is  closed  by  hinged  cast-iron  doors  which  are 
dropped  at  the  end  of  the  day's  run  in  order  to  permit  the  un- 
consumed  fuel  and  the  residue  of  iron  in  the  cupola  to  fall  out 
and  be  removed.  Molten  iron  is  taken  out  through  a  hole  at 
the  bottom  and  slag  is  removed  through  a  hole  in  the  opposite 
side  and  at  a  slightly  higher  level  than  the  iron  tap-hole. 
The  cupola  is  encircled  near  its  base  by  a  chamber,  known  as 
the  wind-box,  communicating  with  the  tuyeres.  The  fan  or 
pressure  blower  furnishing  air  to  the  cupola  delivers  it  to  this 
wind-box  whence  it  finds  its  way  through  the  tuyeres  into  the 
cupola.  It  is  in  the  arrangement  of  the  tuyeres  that  the 
various  cupolas  of  different  makers  differ  principally  from 
each  other.  It  would  be  out  of  place  in  a  book  of  this  char- 
acter to  enter  into  a  discussion  of  the  various  details  of  con- 
struction of  different  cupolas  and  the  reader  is  referred  to  the 
catalogues  of  the  various  foundry-supply  houses  for  informa- 
tion on  this  subject. 

Taking  up  the  construction  in  detail  of  the  cupola  shown  in 
245 


246  FOUNDRY   PRACTICE 

Fig.  140,  the  shell  A  is  formed  of  separate  rings  of  boiler  plate 
riveted  together  with  angles  E  riveted  to  the  interior  at  in- 
tervals to  support  the  fire-brick  lining  L.  The  shell  is  carried 
on  a  cast-iron  bed-plate  ring  B,  which  is  in  turn  supported  by 
the  cast-iron  legs  5.  The  opening  in  this  ring  is  closed  by 
a  pair  of  hinged  drop-doors,  which  when  closed  are  held  in 
place  by  a  rod,  or  spud,  wedged  between  them  and  the  floor. 
At  F  is  seen  the  wind-box  encircling  the  cupola  communicating 
with  the  tuyeres  H  and  /.  At  G  is  the  blast-pipe  connecting 
the  fan  or  blower  with  the  wind-box.  At  C  is  the  breast  built 
around  the  tap-hoi^  T  through  which  iron  is  removed  from 
the  cupola, 'it  flowing  through  a  spout  R.  The  slag-hole  and 
spout  are  shown  at  W.  Iron  and  fuel  are  introduced  into  the 
cupola  through  the  charging  door  D,  and  in  practice  this  door 
is  usually  at  the  level  of  the  second  floor  of  the  foundry  or  a 
platform  is  built  around  it.  Cleaning  doors  are  built  on 
either  side  of  the  wind-box  to  permit  the  removal  of  any  slag 
or  iron  which  may  flow  through  the  tuyeres  into  it.  Opposite 
each  tuyere  a  peep-hole  P  is  provided,  which  is  covered  when 
not  in  use  by  a  swinging  cast-iron  cover.  By  using  these 
peep-holes  the  melter  can  ascertain  in  a  measure  how  the  cupola 
is  operating.  The  tuyeres  are  of  cast-iron  and  flare  inward 
as  shown  in  the  plan,  Fig.  141. 

The  height  of  the  tuyeres  above  the  bed  plate  varies 
according  to  the  class  of  work  done  in  the  foundry.  The 
number  of  rows  of  tuyeres  also  ranges  from  one  to  three.  Thus 
stove-plate  work  does  not  require  a  great  depth  of  iron  to  be 
maintained  in  the  basin,  as  the  space  between  the  bottom  of 
the  cupola  and  the  tuyeres  is  known.  Consequently,  the 
tuyeres  can  be  set  at  a  lower  level  than  in  a  cupola  melting 
iron  for  heavy  engine  castings  where  a  great  volume  of  metal 
may  be  required  at  one  time.  The  advantage  of  using  two  or 
more  rows  of  tuyeres  is  that  gases  may  be  distilled  from  the 
fuel  and  escape  without  coming  in  contact  with  air  blown 
through  the  lower  row.  They  must,  however,  pass  through 
air  blown  through  the  upper  tuyeres  and  thus  become  com- 
pletely consumed.  The  double  row  of  tuyeres,  therefore, 


THE  CUPOLA  AND   ITS   OPERATION 


247 


248 


FOUNDRY   PRACTICE 


renders  possible  economical  operation  and  quick  melting,  inas- 
much as  no  fuel  is  wasted.  When  running  small  heats  the 
upper  row  of  tuyeres  may  be  shut  off  by  means  of  a  damper. 
Also  if  the  cupola  is  melting  more  rapidly  than  is  desired,  the 
upper  tuyeres  may  be  shut  off  and  the  amount  of  air  furnished 
the  cupola  may  be  diminished  by  means  of  a  damper  in  the 
blast-pipe.  Thus  the  melting  rate  of  the  cupola  is  always 
under  control  of  the  melter.  An  arrangement  is  also  provided 


FIG.  141. — SECTIONAL  PLAN  OF  CUPOLA  THROUGH  LOWER  TUYERES. 


whereby  iron  rising  too  high  in  the  basin  before  tapping  will 
run  through  a  spout  into  the  wind-box  where  it  will  melt  a  lead 
plug  and  fall  to  the  floor,  thus  giving  warning  that  the  cupola 
should  be  tapped. 

Cupolas  may  use  either  coke  or  anthracite  coal  for  fuel, 
coke  being  the  most  generally  used.  In  preparing  the  cupol? 
the  bottom  doors  are  closed  and  a  sand  bottom,  usually  com- 
posed of  gangway  sweepings  or  similar  material,  is  built  on 
them.  This  is  tempered  the  same  as  molding  sand  and 
rammed  down  as  in  molding,  being  rammed  harder  at  the 


THE  CUPOLA  AND  ITS  OPERATION  249 

bottom  than  at  the  surface.  It  is  inclined  toward  the  tap-hole 
so  that  the  tendency  will  be  for  all  iron  to  drain  out.  The  fire 
in  the  cupola  may  be  lighted  either  with  wood  or  by  means  of  a 
gas  or  oil  burner.  In  the  former  case  shavings  are  laid  on  the 
bottom  with  enough  wood  over  them  to  insure  thorough  ig- 
nition of  the  coke.  A  bed  charge  of  coke  is  placed  in  the  cupola 
before  any  iron  is  charged  and  this  is  of  considerably  greater 
weight  than  the  subsequent  charges  of  coke  which  are  charged 
alternately  with  charges  of  iron.  A  portion  of  this  bed  charge 
is  laid  on  the  wood  and  after  it  is  thoroughly  ignited  the  re- 
mainder of  it  is  introduced  into  the  cupola,  only  enough  being 
reserved  to  level  off  the  top  of  the  bed  charge  before  intro- 
ducing iron. 

When  the  coke  is  to  be  ignited  by  means  of  a  gas  or  oil 
burner  a  space  is  left  in  front  of  the  breast  opening  and  one  or 
two  channel  ways  are  formed,  leading  nearly  to  the  back  of 
the  cupola,  by  pieces  of  coke  laid  end  to  end,  through  which 
the  flames  of  a  burner  will  pass.  The  channels  are  covered 
with  pieces  of  coke,  and  one-half  to  one-third  of  the  bed  charge 
placed.  The  burner  is  then  laid  in  the  spout  of  the  cupola 
and  kept  back  from  the  breast  opening  a  distance  of  about 
four  inches.  It  is  lighted  and  regulated  so  that  the  flame  at 
the  burner  will  be  blue,  changing  to  purple  tipped  with  yellow. 
It  is  kept  on  until  the  coke  is  thoroughly  ignited,  usually  a 
period  of  thirty  minutes  with  the  oil  burner  and  somewhat 
less  with  the  gas.  On  its  removal,  the  breast  is  built  as  will  be 
described  later  and  the  blast  turned  on  to  thoroughly  ignite 
the  entire  charge  of  coke  on  the  bed.  When  the  blast  is  put 
on,  the  remainder  of  the  bed  charge  is  introduced  into  the 
cupola  with  the  exception  of  enough  reserved  to  level  it  before 
charging  the  iron. 

When  the  fire  is  visible  through  the  coke,  as  viewed  from 
the  charging  door,  and  the  bed  charge  is  leveled,  charging 
should  begin,  as  the  fire  should  not  be  permitted  to 
burn  red  hot.  If  the  coke  appears  to  be  burning  more 
freely  on  one  side  than  on  the  other  some  of  the  coke  reserved 
for  leveling  is  thrown  on  that  side  and  the  peep-holes  opened 


25O  FOUNDRY   PRACTICE 

or  closed  to  force  the  air  to  the  side  which  has  burned  the  least. 
The  more  evenly  the  coke  is  burned  the  better  will  the  cupola 
melt  and  the  better  will  be  the  grade  of  iron  obtained  for  the 
mold. 

The  breast  is  now  built  in  and  the  tap-hole  formed.  Three 
different  methods  of  doing  this  are  in  general  use.  When  the 
shavings  and  wood  used  to  fire  the  cupola  have  burned  away 
the  coke  will  settle  down  on  the  sand  bottom  in  front  of  the 
breast  opening.  Any  coke  that  may  have  fallen  into  the  open- 
ing is  removed  and  a  tapered  iron  pin  is  laid  in  the  tap  spout, 
small  end  in,  projecting  into  the  cupola.  With  small  pieces 
of  coke  a  wall  is  built  in  front  of  the  burning  coke  and  in  front 
of  this  wall  the  same  mixture  of  fire-clay  mud  that  is  used  for 
lining  the  cupola  (see  page  258)  is  rammed,  after  which  the  iron 
pin  is  withdrawn,  leaving  a  tap-hole  in  the  breast.  The  wall  of 
coke  soon  ignites  and  dries  out  the  breast.  The  second 
method  consists  in  building  the  wall  of  coke  as  before,  leaving 
quite  a  space  in  front  of  it.  Wet  shavings  are  forced  against 
the  coke,  after  which  the  pin  is  placed  and  the  fire-clay  breast 
rammed  up  as  before.  The  third  method  utilizes  a  board  with 
a  notch  in  its  lower  edge  which  fits  over  the  tap-hole  pin  and 
which  is  laid  against  the  wall  of  coke.  The  breast  is  built 
against  this  board.  Instead  of  fire-clay  mud,  some  melters 
will  use  for  the  breast  a  mixture  of  molding  sand  wet  with 
claywash,  while  others  make  use  of  any  natural  loam  which 
may  be  found  in  the  vicinity. 

The  breast  being  in,  it  must  be  ascertained  that  the  top  of 
the  bed  charge  is  at  the  correct  height.  Every  cupola  has  a 
melting  zone  above  the  tuyeres  where  it  is  the  hottest,  this 
zone  being  known  as  the  melting  zone.  In  a  cupola  which  has 
been  running  for  some  time,  this  melting  zone  is  easily  ascer- 
tained by  the  condition  of  the  lining  which  will  be  burned 
away  to  a  certain  extent  as  shown  in  Fig.  142.  A  rod  with  one 
end  bent  to  a  right  angle  to  hang  on  the  edge  of  the  charging 
door  may  be  provided,  its  length  being  such  that  it  will  drop 
in  the  cupola  to  the  highest  point  of  the  melting  zone.  The 
bed  charge  should  then  be  brought  up  to  the  lower  end  of  this 


THE   CUPOLA  AND   ITS   OPERATION 


251 


FIG.  142. — CUPOLA  CHARGING  ARRANGEMENT.    Also  shows  effect  of  wear 
on  lining. 


252  FOUNDRY   PRACTICE 

rod.  The  use  of  a  small  amount  of  coke  in  the  bed  charge  will 
lower  the  melting  zone  and  a  large  amount  will  raise  it.  With 
a  new  cupola  some  experimenting  is  necessary  to  ascertain  the 
proper  height  at  which  best  results  will  be  obtained  before  the 
amount  of  bed  charge  and  its  height  are  definitely  determined. 
The  quality  of  the  iron  melted  will  be  influenced  by  this,  as 
scrap  will  -melt  earlier  than  heavy  pig  iron,  and  if  a  large  pro- 
portion of  the  former  material  is  used  the  melting  zone  should 
be  somewhat  lower  than  if  the  bulk  of  the  charge  is  pig  iron. 
The  quality  of  the  melted  iron  is  usually  better  with  a  high  bed 
than  with  a  low  one.  With  a  new  cupola  it  is  advisable  to  be 
on  the  safe  side  and  start  with  a  high  bed,  say  twenty- two 
inches  above  the  upper  tuyeres,  and  by  examination  of  the 
lining  the  following  morning  determine  whether  or  not  the 
amount  of  the  bed  charge  should  be  reduced. 

The  bed  charge  of  coke  having  been  brought  to  the  right 
height,  iron  is  introduced  on  it.  The  amount  of  the  first 
charge  of  iron  varies  with  different  melters,  ranging  all  the 
way  from  two  and  one-half  pounds  of  iron  per  pound  of  coke 
in  the  bed  charge  to  four  pounds  of  iron  per  pound  of  coke. 
The  amount  of  iron  charged  depends  also  on  the  total  amount 
of  iron  to  be  melted  in  the  heat  and  this  also  governs  the  size 
of  the  subsequent  charges  of  iron  and  coke.  Assume  that  our 
first  charge  of  coke  was  I ,500  pounds.  On  this  will  be 
charged  4,500  pounds  of  irorT On  this  charge  of  iron  will  be 
placed  256  pounds  of  coke  and  on  the  coke  a  charge  of_2.,5OO 
pounds  of  iron.  This  ratio  of  coke  and  iron  is  maintained 
throughout  the  remainder  of  the  heat.  The  arrangement  of 
the  various  charges  of  coke  and  iron  is  shown  in  Fig.  143.  We 
will  later  discuss  the  question  of  varying  the  size  and  weight  of 
the  charges  of  coke  and  iron,  with  their  effect  on  the  operation 
of  the  cupola. 

In  charging  with  iron,  the  pig  iron  is  usually  placed  in  the 
cupola  first,  and  on  top  of  this  the  scrap.  The  scrap  being  free 
from  scale  usually  melts  more  rapidly  than  the  pig  iron,  and 
the  pig  iron  being  charged  so  as  to  reach  the  melting  zone  first, 
the  two  are  usually  melted  at  about  the  same  time.  The 


THE   CUPOLA  AND   ITS   OPERATION 


253 


charging  of  coke  and  iron  alternately  continues  until  the  cupola 
is  filled  to  the  desired  height  or  the  amount  of  iron  needed  for 
the  heat  has  been  charged.  If  the  cupola  will  not  hold  enough 
iron  for  the  heat,  after  it  has  been  filled  to  the  level  of  the 


FIG.  143. — CUPOLA  CHARGING  ARRANGEMENTS.     Also  shows  arrangement 
of  coke  and  iron  charges. 


charging  door,  subsequent  charges  are  added  as  the  bed  settles, 
due  to  iron  being  withdrawn  through  the  tap-hole  and  the  coke 
burning  away.  If  heavy  scrap  is  used  it  is  generally  charged 


254  FOUNDRY   PRACTICE 

with  the  second  lot  of  iron,  a  little  coke  being  mixed  with  it  to 
assist  in  its  rapid  melting. 

A  certain  amount  of  slag  is  required  in  cupolas  to  prevent 
the  iron  from  being  burned  away  by  the  action  of  the  blast. 
It  is  also  necessary  to  prevent  the  molten  iron  in  the  basin  from 
being  decarbonized.  Frequently  the  coke  will  contain  suffi- 
cient impurities  to  form  slag  enough  to  protect  the  iron,  but 
with  clean  iron  and  fuel  slag  will  not  form  in  sufficient  quanti- 
ties in  small  heats.  It  is  therefore  necessary  to  introduce  a 
material  to  form  slag;  and  limestone,  marble  dust  or  fluor-spar, 
or  any  other  material  containing  lime,  should  be  charged  with 
the  iron,  commencing  at  about  the  fifth  charge  and  using 
approximately  sixty  pounds  of  limestone  per  ton  of  iron.  The 
particular  amount,  however,  depends  on  local  conditions,  being 
governed  by  the  analysis  of  the  fuel  and  iron  and  also  by  its 
effect  on  the  lining.  Sufficient  slagging  material  must  be 
added  to  insure  the  slag  being  sharply  fluid,  and  yet  any  excess 
of  limestone  will  attack  the  fire-brick  lining  of  the  cupola  and 
will  also  influence  to  a  certain  extent  the  quality  of  the  iron 
melted.  If  marble  dust  is  used,  six  pounds  per  ton  of  iron  will 
usually  give  a  good  slag  of  sufficient  quantity. 

Certain  foundrymen  do  not  slag  their  cupolas,  these  being 
larger  than  are  necessary  to  give  the  amount  of  iron  needed  at 
any  one  time.  However,  if  the  cupola  is  to  be  driven  to  the 
limit  of  its  capacity,  slagging  is  absolutely  essential.  If  the 
quantity  of  slag  formed  is  not  too  great,  it  may  be  allowed  to 
remain  in  the  cupola  until  the  end  of  the  heat.  As  it  rests  on 
top  of  the  iron  in  the  basin  none  of  it  will  run  out  of  the  tap- 
hole  unless  the  level  of  the  iron  is  lowered  to  below  the  upper 
edge  of  the  tap-hole.  However,  if  it  is  necessary  to  use  a 
considerable  quantity  of  slagging  material,  provision  must  be 
made  to  remove  it  through  the  slag-hole  continuously.  If 
allowed  to  accumulate,  it  may  bridge  or  scaffold  above  the 
tuyeres  and  give  trouble  in  the  operation  of  the  cupola. 

The  cupola  being  charged,  it  will  be  well  to  allow  it  to 
stand  for  about  half  an  hour  before  the  blast  is  put  on.  The 
lower  charges  will  then  be  heated  to  such  an  extent  that  when 


THE   CUPOLA   AND   ITS   OPERATION  255 

the  blast  is  put  on  melting  begins  rapidly  and  evenly  and  con- 
tinues at  a  uniform  rate  throughout  the  heat.  The  blast 
being  put  on,  iron  shortly  begins  to  run  sluggishly  from  the  tap- 
hole  which  has  been  left  open.  It  becomes  hotter  and  hotter 
until  finally  it  is  perfectly  fluid.  The  melter  then  closes  the  tap- 
hole  with  a  bod  of  fire-clay  and  allows  the  iron  to  accumulate 
in  the  basin  until  there  is  a  sufficient  quantity  to  pour  the  first 
lot  of  molds.  Should  the  tap-hole  be  closed  as  soon  as  the  iron 
began  to  flow,  the  iron  might  cool  in  the  bottom  of  the  cupola 
and  harden  in  front  of  the  tap-hole,  making  it  extremely  diffi- 
cult to  tap  the  cupola  later.  In  tapping  the  cupola  care  must 
be  taken  that  the  tap-hole  be  kept  free  of  slag  and  iron,  and 
also  that  while  boding  up,  or  closing  the  tap-hole  with  clay, 
parts  of  each  bod  are  not  left  around  the  tap-hole  each  time, 
thus  building  it  out  from  the  breast.  If  this  care  is  not 
taken,  it  will  eventually  become  difficult  or  impossible  to  bod 
up  the  cupola,  and  the  iron  will  run  out  until  the  cupola  is 
empty. 

The  clay  to  form  the  bods  for  the  tap-hole  should  be  one 
that  will  not  bake  too  hard,  else  it  will  require  a  tapping  bar  and 
a  sledge  to  drive  the  bod  out  of  the  hole  when  it  is  desired  to 
tap  the  cupola.  The  clay  used  should  be  one  that  will  bake 
hard  enough  to  hold  the  iron,  yet  one  which  will  break  com- 
paratively easily.  If  the  clay  alone  bakes  too  hard,  white-pine 
sawdust,  seacoal,  or  similar  material  may  be  added  to  it.  The 
tapping-bar  must  be  kept  clean  and  pointed,  which  can  be 
accomplished  by  holding  the  end  in  the  stream  of  iron  flowing 
from  the  cupola.  Before  making  the  hole  in  the  breast,  the 
clay  on  the  breast  around  the  bod  should  be  slightly  cleaned 
with  the  point  of  the  tap-rod,  which  will  prevent  trouble  due 
to  the  bods  building  out  on  the  breast.  In  closing  the  tap-hole 
the  rod  with  the  bod  of  clay  on  the  end  should  be  held  above 
the  stream  of  iron,  and  the  bod  forced  down.  If  it  is  attempted 
to  force  the  bod  up  through  the  iron,  it  is  liable  to  be  washed 
from  the  rod,  which  may  cause  serious  trouble  before  it  can 
be  replaced. 

After  the  cupola  is  in  operation,  the  pouring-spout  should 


256  FOUNDRY    PRACTICE 

be  observed  closely  to  ascertain  when  it  is  necessary  to  open 
the  slag-hole.  When  nearly  all  the  iron  has  run  from  the  basin 
during  a  given  tap,  a  small  quantity  of  slag  may  appear  on 
the  surface  of  the  iron  as  it  flows  down  the  spout.  This  is 
evidence  that  by  the  time  the  basin  has  filled  with  iron  for  the 
next  tap  a  considerable  quantity  of  slag  will  have  accumulated 
on  top  of  the  iron.  Shortly  before  the  next  tap,  therefore,  the 
slag-hole,  which  has  been  closed  with  a  bod  of  molding  sand  and 
molasses  water,  is  opened  and  the  slag  permitted  to  escape. 
After  the  slag  has  once  commenced  to  run  freely,  the  slag-hole 
will  take  care  of  itself,  the  slag  rising  on  top  of  the  iron  as  it 
collects  in  the  basin,  and  flowing  out  through  the  slag-hole 
whenever  it  rises  to  that  level. 

It  is  customary  to  charge  a  few  hundred  pounds  more  of 
iron  into  the  cupola  than  are  required  to  pour  all  the  molds, 
as  the  last  iron  out  of  the  cupola  always  has  more  or  less  slag 
on  it,  which  would  render  defective  castings  which  later  must 
be  machined.  Consequently  the  last  castings  to  be  poured 
should  be  those  of  a  rough  character  requiring  no  machining. 
If  all  the  castings  are  to  be  of  a  good  character  the  iron  cannot 
be  totally  drained  from  the  cupola  for  them  and  the  last  few 
hundred  pounds  are  run  into  ingot  molds  or  pig  beds.  When 
all  the  iron  has  been  drained  from  the  cupola,  the  spud  is 
knocked  from  beneath  the  bottom  doors  or  pulled  out  by 
means  of  a  compressed  air  attachment,  and  the  coke  in  the 
cupola  falls  to  the  floor.  In  most  large  foundries  a  series  of 
iron  hooks  are  placed  under  the  cupola,  points  upward,  so  that 
the  mass  of  coke  may  be  pulled  from  under  the  cupola  by  means 
of  a  chain  and  a  compressed  air  hoist,  thus  tearing  the  mass 
apart  and  distributing  it  so  that  it  can  be  readily  quenched 
by  a  stream  from  a  hose  and  considerable  coke  thereby  saved. 
It  is  absolutely  essential  that  the  spot  on  which  the  mass  from 
the  cupola  drops  be  perfectly  dry.  Otherwise  there  will  be  a 
generation  of  steam  which  in  expanding  will  throw  the  red-hot 
coke  in  all  directions,  burning  the  workmen  and  doing  damage 
to  the  building.  Occasionally,  when  the  drop  takes  place, 
all  the  material  above  the  tuyeres  does  not  come  with  it,  being 


THE   CUPOLA   AND   ITS   OPERATION  257 

scaffolded  in  the  cupola.  However,  as  the  coke  burns  away 
during  the  night  this  material  will  fall,  although  occasionally 
it  has  to  be  poked  down  by  means  of  bars  inserted  through  the 
peep-holes  in  the  tuyeres  or  broken  down  by  pigs  of  iron  thrown 
through  the  charging  door.  This  latter  occurrence  happens 
most  often  when  the  cupola  is  not  slagged. 

The  following  day  the  lining  of  the  cupola  should  be  in- 
spected and  repaired  before  it  is  charged  for  that  day's  run. 
Cupolas  are  built  with  either  a  single  or  double  lining,  the  first 
consisting  of  a  lining  of  heavy  cupola  blocks  of  fire-brick,  the 
second  of  two  rows  of  fire-brick  one  inside  the  other.  The 
advantage  of  the  double  lining  is  that  it  is  considered  to  give 
greater  protection  to  the  shell,  while  the  single  lining  permits 
relining  to  be  accomplished  more  quickly  than  does  the  double 
lining.  It,  however,  requires  more  careful  watching  than  the 
other  and  may,  if  not  attended  to,  break  through  at  a  time 
when  the  cupola  is  in  operation,  which  will  be  evidenced  by  the 
shell  becoming  red  hot  opposite  the  hole  in  the  lining.  If 
possible,  this  spot  should  be  cooled  by  a  plentiful  application 
of  cold  water  to  the  shell  and  the  cupola  kept  in  operation  until 
the  heat  is  finished.  However,  if  the  red  spot  shows  a  ten- 
dency to  enlarge,  the  blast  should  be  shut  off  and  the  bottom 
dropped.  It  is  sometimes  possible  to  repair  temporarily  a 
break  in  the  lining  while  the  cupola  is  in  operation  by  throwing 
in  fire-brick  and  fire-clay  mud  through  the  charging  door  im- 
mediately above  the  place  where  the  hot  spot  shows.  These 
will  fuse  and  find  their  way  into  the  break  and  repair  it  suffi- 
ciently to  finish  the  heat.  Wetting  down  of  the  shell  should 
continue  nevertheless  until  the  heat  is  ended. 

The  care  of  the  lining  and  the  method  of  charging  have 
much  to  do  with  the  life  of  the  cupola.  The  fact  that  the  lining 
burns  out  rapidly  is  not  necessarily  an  indictment  against  the 
brick  of  which  it  is  composed,  but  may  indicate  lack  of  care  on 
the  part  of  the  melter.  In  lining  the  cupola  for  the  first  time, 
a  space  of  about  five-eighths  inch  should  be  left  between  the 
back  of  the  brick  and  the  shell  of  the  cupola,  and  grouting — 
a  thick  claywash — poured  in  behind  them.  The  fire-brick 
17 


258  FOUNDRY    PRACTICE 

composing  the  lining  are  set  in  a  thick  claywash,  termed  butter. 
The  brick  should  be  laid  as  closely  together  as  possible  and  the 
rows  buttered  together.  The  brick  are  grouted  at  the  back  to 
avoid  chipping  where  they  come  against  rivets  in  the  shell,  and 
they  must  be  carefully  fitted  around  the  tuyeres  and  lining 
shelves.  Otherwise  they  are  laid  up  in  regular  rows,  with  broken 
joints.  The  lining  below  the  level  of  the  charging  door  is 
considerably  thicker  than  it  is  above,  as  this  portion  of  it  not 
only  has  to  resist  the  more  intense  heat  but  also  the  abrasion 
of  the  fuel  and  iron.  Frequently  the  lining  above  the  charging 
door  is  composed  simply  of  common  red  brick  of  good  quality. 
After  the  lining  is  completed  it  should  be  thoroughly  dried  out 
by  a  fire  built  in  the  bottom  of  the  cupola. 

A  lining  built  as  above  must  be  repaired  after  each  heat 
with  a  mud  composed  of  sand  and  clay  wet  with  water, 
all  foreign  matter  which  may  be  clinging  to  the  lining  being 
first  removed  with  a  pick  or  chisel,  care  being  taken  not  to 
break  away  the  surface  of  the  lining  if  it  can  be  avoided.  The 
mud  is  applied  by  throwing  it  in  handfuls  against  worn  spots 
in  the  lining  and  afterward  smoothing  it  with  a  trowel  so  as 
to  conform  as  closely  as  possible  with  the  original  shape  of  the 
lining.  The  slag-hole  is  formed  by  placing  a  gate-stick  at  the 
proper  point  and  daubing  mud  around  it,  afterward  removing 
the  stick  and  filling  the  opening  with  a  mixture  of  sand  and 
molasses  water.  The  cupola  lining  will  require  but  little  re- 
pairing during  the  first  few  heats,  but  after  a  long  period  of 
operation  holes  of  considerable  size  may  be  burned  in  it  and 
these  should  be  filled  with  small  pieces  of  fire-brick  and  the  mud 
laid  in  around  them.  The  space  to  be  repaired  in  a  cupola 
usually  extends  some  three  or  four  feet  above  the  tuyeres  as 
shown  in  Fig.  142,  and  also  in  Fig.  144,  the  latter  illustrating 
the  method  of  making  certain  classes  of  repairs.  When  the 
variety  of  clay  available  for  lining  repairs  is  of  poor  quality, 
a  large  quantity  of  sand  of  high  fusion  should  be  mixed  with 
it  to  render  it  more  refractory.  If  the  fusing  point  of  the  clay 
is  low,  the  mud  repair  may  melt  and  run  down  and  choke  the 
tuyeres  as  shown  in  Fig.  144.  Again,  the  daubing  may  become 


THE  CUPOLA  AND  ITS  OPERATION 


259 


broken  away  and  permit  the  charge  to  enter  in  back  of  it  as 
shown  in  the  same  illustration,  finally  breaking  the  lining  away 
and  scaffolding  the  cupola.  When  this  occurs  the  iron  melts 
slowly,  as  the  charge  cannot  work  its  way  down  to  the  melting 
zone  and  it  is  necessary  to  drop  the  bottom  and  thus  lose  the 


LINING  MELTII 
RUNNING  DOV 

TUYERE 


INING  CRACKING 

>M   BRICK.    COKE  FOLLOWING 

IN   BETWEEN,  AND 
THROWING  CHARGES. 


PROPER  WAY  TO  REPAIR   BADLY 


FIG.  144. — FAILURES  OF  CUPOLA  LININGS  AND  CORRECT  AND  INCORRECT 
METHODS  OF  MAKING  REPAIRS. 

heat.     The  proper  method  of  making  extensive  repairs  to  the 
lining  is  also  shown  in  this  illustration. 

A  great  deal  of  useful  information  regarding  the  operation 
of  the  cupola  is  given  by  Bradley  Stoughton  in  an  article  in 
The  Foundry  in  October,  1907.  Mr.  Stoughton  divides  the 
cupola  into  four  zones:  (i)  The  crucible  zone  or  hearth  extend- 
ing from  the  bottom  of  the  cupola  to  the  tuyeres.  (2)  The  tuyere 
rone  where  the  blast  comes  in  contact  with  and  burns  the 
red-hot  coke.  This  is  the  zone  of  combustion.  Its  upper 
limit  depends  on  the  blast  pressure,  and  the  higher  the  pres- 
sure the  greater  will  be  the  height  of  the  zone.  The  top  of  the 
zone  should  never  be  allowed  to  go  15  to  24  inches  above  the 
tuyeres.  (3)  The  melting  zone  where  all  melting  takes  place. 
It  is  situated  immediately  above  the  tuyere  zone  and  the  lower 
part  of  it  overlaps  the  latter.  Iron  of  the  charge  should  begin 
to  melt  as  soon  as  it  enters  the  melting  zone  and  should  finish 
melting  at  a  point  about  seven  inches  lower  down,  the  iron 
and  coke  sinking  as  the  latter  burns  away.  Each  charge  of 
iron  should  enter  the  melting  zone  just  before  the  last  previous 
charge  is  completely  melted  at  the  bottom.  (4)  The  stack  ex- 


260  FOUNDRY   PRACTICE 

tending  from  the  melting  zone  to  the  level  of  the  charging  door. 
Its  function  is  to  contain  the  material,  permitting  it  to  absorb 
heat  and  thus  prepare  itself  for  the  action  at  the  lower  level. 

The  blast  pressure  should  depend  on  the  size  of  the  cupola, 
but  present  practice  favors  a  pressure  of  not  over  one  pound 
per  square  inch,  diminishing  to  one-half  pound  in  the  smaller 
sizes  of  cupolas.  As  one  pound  of  coke  requires  about  sixty 
cubic  feet  of  air  for  burning  it,  the  size  of  the  blower  necessary 
may  be  calculated.  Makers  of  blowers  advocate  pressures 
and  volumes  too  high  for  good  cupola  practice.  If  the  pressures 
and  volumes  advocated  by  them  are  adopted  unqualifiedly, 
the  melting  zone  will  be  raised  and  the  iron  oxidized,  due  to  its 
greater  drop  to  the  hearth  through  the  incoming  blast. 

Melting  should  begin  within  fifteen  minutes  of  the  time 
that  the  blast  is  put  on.  If  it  takes  longer  than  this  the  bed 
charge  of  coke  has  been  made  too  high  and  coke  is  wasted. 
The  first  layer  of  iron  should  be  completely  melted  in  eight  to 
ten  minutes.  The  thickness  of  the  various  layers  of  coke  should 
be  such  that  the  next  layer  of  iron  should  enter  the  melting 
zone  just  as  the  previous  one  is  melted.  If  the  layers  of  coke 
are  made  thicker  than  this,  coke  is  wasted.  If  the  iron  layer 
is  too  thick  the  last  of  the  layer  will  melt  near  the  tuyeres  and 
will  oxidize  excessively  and  be  cold.  The  fact  that  the  iron 
layers  are  too  thick  may  be  noted  by  the  iron  running  first  hot 
and  then  cold  from  the  cupola  spout. 

It  is  important  to  watch  the  flames  from  the  stack.  Too 
great  a  volume  of  blast  is  indicated  by  a  "cutting"  or  oxidizing 
flame,  and  also  by  the  projection  of  sparks  from  the  slag-hole. 
If  the  layers  of  iron  and  coke  are  too  thin,  there  will  be  two 
charges  of  iron  in  the  melting  zone  at  one  time.  This  will  be 
made  evident  by  the  iron  flowing  more  freely  from  the  cupola 
spout  at  one  time  than  another.  If  very  hot  iron  is  desired 
the  coke  layers  must  be  made  thicker,  with  a  consequent 
diminution  in  the  rate  of  melting. 

Concerning  the  absorption  of  sulphur  by  the  iron  from  the 
fuel,  Mr.  Stoughton  says  that  the  absorption  will  range  from 
0.020  to  0.035  Per  cent  and  that  pig-iron  with  a  sulphur  con- 


THE  CUPOLA  AND  ITS  OPERATION          26l 

tent  of  0.08  per  cent  will  give  castings  in  which  the  sulphur 
will  range  from  o.io  to  0.115  per  cent.  The  sulphur  will  be 
higher  in  the  first  iron  to  come  down  than  in  the  iron  ob- 
tained at  the  middle  of  the  heat  because  of  the  extra  amount  of 
coke  in  the  bed  charge.  The  iron  obtained  at  the  end  of  the 
heat  will  also  be  higher  in  sulphur  because  of  the  greater  loss  of 
metal  at  the  end  of  the  run  due  to  better  oxidizing  condi- 
tions and  consequently  greater  concentration  of  the  metal. 
Silicon  to  the  extent  of  0.25  to  0.40  per  cent  may  be  burned  out 
of  the  iron  in  its  passage  through  the  cupola.  An  allow- 
ance must  be  made  for  this  in  calculating  the  character  of  the 
charge. 

In  this  same  article,  Mr.  Stoughton  published  a  table  of 
comparative  cupola  practice  which  is  reproduced  below. 
Commenting  on  this  table,  Mr.  Stoughton  says  that  a  mixture 
of  coal  and  coke,  or  an  inferior  coke  gives  slow  melting  and  a 
poor  fuel  ratio.  The  next  striking  evidence  from  the  table  are 
the  figures  given  by  the  relation  of  the  tuyere  area  to  the 
speed  of  melting.  If  an  average  iron  is  melted  in  cupolas 
whose  area  is  less  than  6.56  times  the  tuyere  area,  we  have 
a  melting  speed  of  22.56  pounds  per  minute.  For  lesser 
proportional  tuyere  areas  the  figure  is  18.57  pounds.  Slow 
melting  in  cupola  No.  8  is  evidently  due  to  the  low  height  of 
the  stack,  which  caused  the  iron  to  reach  the  melting  zone 
before  it  was  sufficiently  preheated.  A  large  proportional 
tuyere  area  means  that  the  blast  passes  through  the  tuyeres 
with  less  resistance  and  with  lower  velocity.  An  important 
figure  in  the  table  is  the  relation  between  the  speed  of  melting 
and  the  height  of  the  charging  door  above  the  tuyeres,  divided 
by  the  diameter  of  the  cupola.  The  average  melting  speed 
where  this  ratio  is  over  2.5  is  24.12  pounds  per  minute. 
When  the  ratio  is  under  2.5,  the  melting  speed  drops  to  19.15 
pounds  per  minute.  An  exception  to  this  rule  is  shown  by 
cupolas  Nos.  6  and  3.  Cupola  No.  6  melts  faster  due  to  its 
larger  proportional  tuyere  area,  while  cupola  No.  3  melts 
slower  due  to  its  lower  proportional  tuyere  area.  The  average 
speed  of  melting  with  cupolas  of  more  than  12  ounces  blast 


262 


FOUNDRY   PRACTICE 


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u  S  o 


THE    CUPOLA   AND    ITS    OPERATION 


263 


pressure  is  20.75  pounds  per  minute,  while  the  rate  with  less 
than  12  ounces  is  21.53.  .The  divergence  here  is  not  great 
enough  to  establish  a  rule,  but  it  is  sufficient  to  discredit  the 
theory  that  a  high  blast  pressure  necessarily  gives  fast  melting. 
This  last  statement  is  apparently  borne  out  by  an  article 
by  Mr.  W.  B.  Snow,  published  in  The  Foundry  in  August, 
1908.  Mr.  Snow  gives  a  table  showing  the  record  of  capacity 
and  the  blast  pressure  of  a  number  of  cupolas  as  follows: 

TABLE  XI. — CAPACITY  AND  BLAST  PRESSURE  OF  CUPOLAS 


Diameter  of  lining, 

in  

44 

44 

47 

49 

54 

54 

54 

60 

60 

60 

74 

Tons  per  hour  

6.7 

7-3 

8.4 

9-1 

7-7 

8.8 

10.2 

12.4 

14.8 

13.8 

13-0 

Pressure,  oz.  per  sq. 

in  

12.9 

16.4 

I7-S 

II.8 

13-6 

II.  O 

20.8 

15.5 

16.8 

12.6 

8.7 

Mr.  Snow  says  that  for  a  given  cupola  and  blower  the 
melting  rate  increases  with  the  square  root  of  the  pressure. 
Thus  a  cupola  which  melts  nine  tons  per  hour  with  a  pressure 
of  10  ounces  will  melt  about  ten  tons  with  a  pressure  of 
12.5  ounces  and  n  tons  with  15  ounces.  The  power  re- 
quired varies  as  the  cube  of  the  melting  rate,  so  for  n  tons 
(n  •*•  9)3  =  1.82  times  as  much  power  will  be  required  as 
for  9  tons.  Thus  large  cupolas  and  blowers  using  light  pres- 
sures have  a  distinct  advantage. 

The  ratio  of  iron  to  fuel  in  the  cupola  is  shown  by  a  series 
of  tables  in  the  eighth  edition  of  Kent's  "Mechanical 
Engineers'  Pocket-Book,"  page  1227.  These  are  taken  from 
the  charging  list  of  several  stove  foundries. 


TABLE  XII 

Bed  of  fuel,  coke 1,500  Ib. 

First  charge  of  iron 5,ooo  Ib. 


All  other  charges  of  iron 

First  and  second  charges  of  coke,  each . 

Four  next  charges  of  coke,  each 

Six  next  charges  of  coke,  each 

Nineteen  next  charges  of  coke,  each. .  . 


[  ,000  Ib. 
200  Ib. 
150  Ib. 
120  Ib. 
100  Ib. 


264  FOUNDRY   PRACTICE 

Thus  for  a  melt  of  18  tons,  5,120  pounds  of  coke  are  re- 
quired, giving  a  melting  ratio  of  7  to  i.  If  the  amount  of  iron 
melted  is  increased  to  24  tons,  the  melting  ratio  of  8  pounds 
of  iron  to  one  of  coke  is  obtained. 

TABLE  XIII 

Bed  of  fuel,  coke 1,600  Ib. 

First  charge  of  iron 1 ,800  Ib. 

First  charge  of  fuel 150  Ib. 

All  other  charges  of  iron,  each 1,000  Ib. 

Second  and  third  charges  of  fuel,  each 130  Ib. 

All  other  charges  of  fuel,  each 100  Ib. 

For  an  1 8-ton  melt,  5,060  pounds  of  coke  are  needed,  the 
melting  ratio  thus  being  7.1  pounds  of  iron  to  one  pound  of 
coke. 

TABLE  XIV 

Bed  charge  of  coke 1,600  Ib. 

First  charge  of  iron 4,000  Ib. 

First  and  second  charges  of  coke,  each 200  Ib. 

All  other  charges  of  iron,  each 2,000  Ib. 

All  other  charges  of  coke,  each 150  Ib. 

Thus  4,100  pounds  of  coke  will  be  required  to  melt  18  tons 
of  iron,  giving  a  melting  ratio  of  8.5  to  I. 

TABLE  XV 

Bed  charge  of  fuel,  coke 1,800  Ib. 

First  charge  of  iron 5>6oo  Ib. 

All  charges  of  coke,  each 200  Ib. 

All  charges  of  iron,  each 2,900  Ib. 

The  melting  ratio  in  a  melt  of  18  tons  is  9.4  pounds  of  iron 
to  one  pound  of  coke,  3,900  pounds  of  fuel  being  used. 

TABLE  XVI 

Bed  of  fuel,  coal 1,900  Ib. 

First  charge  of  iron 5,ooo  Ib. 

First  charge  of  coal 200  Ib. 

All  other  charges  of  iron,  each 2,000  Ib. 

All  other  charges  of  coal,  each 175  Ib. 


THE  CUPOLA  AND  ITS  OPERATION          265 

The  melting  ratio  in  a  melt  of  18  tons  is  7.7  pounds  of  iron 
to  one  pound  of  coal,  4,700  pounds  of  coal  being  used. 

Calculating  Cupola  Mixtures. — To  produce  uniformly 
good  castings,  materials  must  be  uniform  and  all  supplies  in- 
cluding pig  iron,  coke,  etc.,  should  be  analyzed  and  their  com- 
position determined.  By  calculating  charges  which  have  been 
put  into  the  cupola,  and  comparing  these  calculations  with 
the  analyses  of  good  castings  made  from  these  charges, 
melting  losses  and  changes  in  composition  of  the  iron 
occurring  in  the  cupola,  can  be  ascertained.  After  the 
melting  factor  has  thus  been  determined,  proper  mixtures 
can  be  made  and  the  cupola  can  be  studied  to  still  further 
improve  the  quality  of  its  output.  What  follows  in  regard 
to  this  subject  is  abstracted  from  a  lecture  by  Dr.  Richard 
Moldenke,  before  the  students  of  the  Case  School  of  Applied 
Science. 

If  the  analysis  of  a  series  of  good  boiler  castings  shows  that 
they  should  contain  about  1 .90  per  cent  silicon,  not  over  0.05 
per  cent  sulphur,  and  not  over  0.40  per  cent  phosphorus,  the 
carbon  and  the  manganese  being  those  of  normal  irons,  then 
the  mixture  must  contain  the  silicon  wanted,  plus  that  burned 
out  during  the  melting  (about  0.25  per  cent).  The  sulphur 
of  the  mixture  must  be  at  least  o.oi  per  cent  lower,  as  this 
amount  is  always  added  by  unavoidable  contact  with  the  fuel. 
The  phosphorus  need  be  but  slightly  lower,  as  the  melting  acts 
somewhat  in  the  way  of  concentration,  the  bulk  of  the  heat 
becoming  4  to  7  per  cent  smaller,  which  percentage  is  called 
the  melting  loss. 

In  calculating  mixtures  we  must  deal  with  the  following 
elements:  Pig  iron,  scraps  of  various  kinds,  the  fuel,  and  the 
limestone  flux.  The  pig  iron  may  have  been  cast  either  in  the 
sand  bed  of  the  blast  furnace  or  in  chill  molds,  and  it  may  be 
either  charcoal,  coke,  or  anthracite  iron,  depending  on  the  fuel 
with  which  it  is  smelted.  Furthermore,  it  may  be  either 
cold-blast  or  warm-blast  charcoal  pig  iron.  The  order  of  ex- 
cellence is  from  the  finest  cold-blast  charcoal  iron  down  to  the 
poorest  cinder-made,  hot-blast  coke  iron.  Cupola  mixtures 


266  FOUNDRY    PRACTICE 

may  contain  only  one  variety  or  can  be  built  up  from  twenty- 
three  pig-iron  ingredients. 

The  scrap  used  may  be  either  made  in  the  foundry  or 
bought.  The  former  is  simply  the  bad  castings,  the  gates 
and  sprues  of  previous  melts,  and  we  should  know  all  about  it. 
The  bought  scrap,  however,  will  often  upset  all  calculations  as 
to  quality,  when  used  in  too  great  a  quantity.  In  addition 
we  may  add  steel  scrap  to  strengthen  castings  and  then  malle- 
able scrap,  wrought-iron  scrap,  cast-iron  borings,  steel  borings, 
etc. 

The  chemical  composition  is  the  basis  of  all  preparations 
and  mixtures  for  building  up  a  heat  for  castings.  The  prep- 
aration of  a  mixture  begins  when  the  pig  iron  is  received  in  the 
foundry  yard.  The  metal  should  be  piled  in  such  a  way  that 
the  foundryman  may  be  sure  of  uniform  material  when  he  uses 
it.  This  is  best  done  by  spreading  the  first  car-load  of  a  given 
composition  in  a  long  row  of  pigs.  The  next  car-load  goes  on 
top  of  this  and  so  on  till  the  pile  is  man  high.  Another  pile  is 
then  commenced.  By  drawing  from  the  end  of  the  first  pile, 
an  average  of  all  the  car-loads  thus  stacked  is  obtained  and  one 
analysis  will  do  for  many  car-loads  of  pig  iron.  In  this  way 
one  can  use  specifications  to  an  advantage,  for,  with  a  given 
class  of  work,  such  as  miscellaneous  car  castings,  it  is  possible 
to  specify,  say,  four  grades  of  iron  containing,  respectively, 
silicon  contents  of  1.75,  2.00,  2.25,  and  2.50.  Of  the  two 
extremes,  but  little  will  be  wanted,  but  the  bulk  will  be  2.25 
silicon  iron.  Now  by  placing  all  car-loads  with  less  than  ten 
points  of  silicon  below  that  required  on  the  next  lower  pile, 
a  satisfactory  arrangement  is  obtained  and  one  can  build  up 
a  mixture  at  the  desk  and  be  sure  that  it  will  work  out  right. 

In  general,  the  more  scrap  used,  the  cheaper  the  mixture, 
but  also  the  greater  the  melting  loss.  A  good  mean  is  usually 
60  per  cent  pig  and  40  per  cent  scrap.  This  is  for  general 
jobbing  castings,  as  special  classes  of  work  often  require  pig 
iron  only.  In  calculating  a  mixture,  suppose  that  the  limit 
for  silicon  be  2.15  per  cent  in  the  castings,  then  the  0.25  per 
cent  lost  in  melting  added  to  this  will  g.ive  us  a  requirement 


THE    CUPOLA    AND    ITS    OPERATION  267 

of  2.40  per  cent  silicon  in  the  mixture.  Assume  the  cupola 
to  be  charged  in  4,ooo-pound  layers  of  metal  with  the  coke-to- 
iron  ratio  one  to  eight.  Of  these  4,000  pounds  of  metal  which 
should,  at  2.40  per  cent  silicon  contain  96  pounds  of  silicon, 
the  pig  iron  is  to  form  60  per  cent  of  the  charge  or  2,400 
pounds,  and  40  per  cent  or  1,600  pounds  should  be  scrap. 
Scrap  usually  contains  less  silicon  than  the  castings  of  the 
particular  class  from  which  the  scrap  originated  and,  therefore, 
for  our  purpose,  the  scrap  may  be  considered  to  contain  2.00 
per  cent  silicon,  or  32  pounds.  The  pig  iron  must  contain  the 
other  64  pounds  and  hence  must  have  an  approximate  silicon 
content  of  2.65.  This  example,  which  by  the  way  is  of  soft 
machine  castings  of  medium  size,  shows  that  the  yard  must 
contain  irons  of  higher  silicon  contents  than  those  given  above. 
They  should  run  in  this  case  2.00,  2.25,  2.50,  and  2.75  per  cent. 
We  note  that  with  pig  irons  averaging  2.65  per  cent  silicon 
desired,  the  mixture  will  be  from  irons  between  the  2.50  and 
the  2.75  limits.  A  simple  trial  calculation  shows  that  2,000 
pounds  of  the  2.75  mixture  and  400  pounds  of  the  2.50  silicon 
iron  will  give  the  proper  results.  The  mixture  table  is  as 
follows : 

1,600  lb.  scrap,  2.00  per  cent  Si 32.0  Ib.   Si. 

2,000  lb.  pig  iron,  say  Warwick,  2.75  per  cent  Si.  ...  55.0  lb.   Si. 
400  lb.  pig  iron,   say  Clifton,   2.50  per  cent  Si.  ...  10.0  lb.   Si. 


4,000  Average  2.40  97.0 

It  is  advisable  to  have  in  the  foundry  yard  a  quantity  of 
iron  containing  4.00  to  5.00  per  cent  silicon  to  correct  a  sudden 
tendency  downward  of  the  silicon  in  the  mixture  as  the  result 
of  an  improper  working  of  the  cupola  or  furnace.  This  also 
enables  us  to  use  lower  silicon  and  therefore  cheaper  irons 
in  the  mixture.  However,  this  is  not  conducive  to  the  best 
results  which  are  obtained  by  putting  into  the  cupola  a§  nearly 
as  possible  what  is  desired  to  obtain  from  it. 

In  charging  steel  scrap,  this  must  be  selected  from  boiler- 
plate, structural  material,  or  steel  castings  if  obtainable.  It 


268  FOUNDRY    PRACTICE 

must  be  neither  too  thick  nor  too  thin,  otherwise  an  irregular 
melting  will  result.  Twenty-five  per  cent  is  a  good  amount 
to  use  for  very  strong  work.  It  can  be  increased  to  40.00  per 
cent  if  desired,  but  anything  above  25.00  percent  will  take  up 
so  much  carbon  from  the  fuel  that  the  value  as  a  reducer  of 
the  total  carbon  is  gone.  Where  much  steel  is  used,  from  2.00 
to  4.00  per  cent  of  ferro-manganese  should  be  put  in  the  ladle, 
as  the  added  steel  raises  the  melting  point  of  the  metal  and  the 
ferro-manganese  is  able  to  act  as  a  deoxidizer  which  is  im- 
possible with  the  low  temperatures  of  ordinary  gray  iron. 

Sulphur  must  be  kept  low  or  there  will  be  trouble  with 
light  castings.  The  calculation  of  sulphur  in  a  mixture  is 
similar  to  that  given  above  for  silicon,  but  if  precautions  are 
taken  to  keep  the  pig  iron  low  in  sulphur,  this  element  need 
not  be  considered  in  mixture  calculations.  Not  only  do  we 
have  to  contend  with  sulphur  in  the  iron  but  also  in  the  fuel. 
From  o.oi  per  cent  to  0.07  per  cent  is  added  to  the  iron  in 
the  cupola,  depending  on  the  sulphur  in  the  fuel.  It  seems 
that  only  the  sulphur  which  is  in  the  ash  of  the  coke  enters 
the  iron  and  especially  when  the  heat  is  run  cold.  It  is  there- 
fore best  to  use  plenty  of  fuel  to  get  a  good  hot  iron,  and  most 
of  the  sulphur  will  be  driven  off  before  it  has  a  chance  to  com- 
bine with  the  iron. 

While  the  importance  of  silicon  and  sulphur  has  been 
specially  dealt  with,  it  is  their  effect  on  the  relations  on  the 
carbon  content  of  the  iron  that  is  really  aimed  at.  Whether 
a  piece  of  iron  is  gray  and  soft,  gray  and  hard,  mottled  or 
white  and  amenable  only  to  the  emery  wheel  depends  to  a 
large  extent  upon  the  proportion  of  combined  carbon  present. 
Thus  in  3.3  per  cent  total  carbon  of  which  0.2  is  combined 
and  3.3  per  cent  is  graphitic,  the  casting  is  practically  a  2O-car- 
bon  steel,  although  it  is  a  soft  gray-iron  casting.  If  the  total 
carbon  is  diminished  to  2.80  per  cent  with  the  combined 
carbon  the  same,  we  have  a  much  stronger  iron,  yet  one  which 
is  easily  machined.  If  the  combined  carbon  is  increased  the 
matrix  becomes  a  tool  steel  with  whatever  graphitic  carbon 
is  present  to  weaken  the  metal.  This  casting,  however,  is 


THE    CUPOLA    AND    ITS    OPERATION  269 

now  hard  to  machine.  Increase  the  combined  carbon  to  the 
full  amount  of  the  total  carbon,  and  we  have  a  white  iron 
such  as  is  used  for  rolls,  malleable  castings,  etc.,  and  which 
usually  require  subsequent  treatment  to  make  them  service- 
able. The  state  of  the  graphitic  and  combined  carbon  in  the 
casting  is  the  result  of  several  variable  conditions.  The  silicon 
content  when  above  1.75  per  cent  makes  gray  to  black 
fractures  in  a  casting,  and  when  below  may  make  fractures 
ranging  from  light  gray  to  dead  white.  The  second  vari- 
able is  the  thickness  of  the  casting  which  controls  the  cool- 
ing rate  after  the  metal  is  poured.  Lastly,  the  temperature 
of  the  melt  has  its  effect,  a  hot  pour  making  a  harder  iron 
than  a  cool  one. 

The  making  of  a  good  mixture  is  not  a  guarantee  that  the 
castings  will  be  right,  for,  after  tapping,  there  are  many 
opportunities  to  spoil  good  work.  The  metal  may  be  poured 
too  hot  or  held  too  long  before  pouring.  The  molds  may  be 
badly  vented  and  the  iron  may  be  poured  so  that  it  will  shot 
or  so  that  slag  enters  the  mold.  Hence  the  necessity  of  cool- 
ness and  good  judgment  in  applying  remedies  for  manifest 
evils  lest  greater  ones  result. 

The  following  method  for  calculating  mixtures  for  the 
cupola  is  given  in  The  Foundry,  October,  1907:  "  It  is  required 
that  the  analyses  of  the  iron  from  the  cupola  be  as  follows: 
Silicon  i. 60  per  cent,  phosphorus  0.70  per  cent,  sulphur 
less  than  o.io  per  cent,  manganese  less  than  0.50  per  cent. 
Previous  experience  with  iron  and  coke  shows,  due  considera- 
tion being  given  to  local  melting  conditions,  that  the  approxi- 
mate loss  of  silicon  in  the  cupola  will  be  0.25  per  cent  and  of 
manganese  o.io  per  cent,  the  sulphur  increasing  at  the 
same  time  0.03  per  cent.  The  iron  and  the  scrap  to  be 
charged,  therefore,  must  have  an  average  analysis  as  follows: 
Silicon  1.85  per  cent,  phosphorus  0.70  per  cent,  sulphur  less 
than  0.07  per  cent,  manganese  0.60  per  cent.  A  table 
similar  to  that  given  below  is  then  made,  showing  various 
weights  of  metal  to  be  charged,  the  analyses  of  the  different 
metals,  and  the  weight  of  silicon,  sulphur,  phosphorus,  and 


2-0 


FOUNDRY   PRACTICE 


manganese  contained  in  a  given  quantity  of  each  iron.  From 
the  classes  of  metal  available  to  form  the  mixture,  selections 
are  made  of  the  proper  quantity  to  give  the  respective  amount 
of  silicon,  sulphur,  phosphorus,  and  manganese  necessary  to 
give  the  desired  average  composition.  The  weight  of  each 
element  is  found  by  multiplying  the  percentage  of  each  ele- 
ment in  the  different  classes  of  material  charged  by  the 
weight  of  that  material,  and  by  dividing  the  total  weight  of 
each  element  by  the  total  weight  of  the  material  charged, 
the  percentage  composition  of  the  mixture  is  determined. 
By  making  adjustments  of  the  pig  iron  and  scrap,  mixtures 
of  any  desired  analysis  can  be  made." 


TABLE  XVII. — MATERIAL  TO  BE  CHARGED  AND  METHOD  OF  FIGURING 


ANALYSIS  PER  CENT 

WEIGHT  OF  * 

Si 

S 

p 

Mn 

Si 

S 

P 

Mn 

Steel  scrap  

400 

O.IO 

0.07 

O.IO 

0.60 

0.40 

0.28 

0.40 

.40 

Machinery  scrap  
High  sulphur  Southern  

2,000 
i,  600 

1.70 
0.70 

O.IO 
O.  IO 

1  .00 
1.50 

0.60 
0.30 

34-00 
ii  .20 

2.OO 
I.  60 

2O.OO 
24.OO 

i    .00 
.80 

No.  IX  

i,  600 

3.00 

0.03 

0,80 

1.25 

48.00 

0.48 

12.80 

2     .OO 

No.  3  foundry  
High  silicon  

4,000 
800 

i.  75 
3.SO 

0.07 
0.025 

0.30 
0.07 

0.60 
0.60 

70.00 
26.00 

2.80 
O.2O 

12.00 
0.56 

i    .80 

<  .80 

Total  
Percentage  

10,400 

191  .60 
1.84 

7.36 
O.O?! 

69.76 
O.67 

68.00 
0.65 

*  Multiply  the  weight  of  each  kind  of  material  by  the  percentage  of  the  element  in  it 
and  divide  total  weight  of  each  element  by  total  weight  of  material.  By  relative  adjustment 
of  pig  iron  and  scrap,  mixtures  for  any  desired  analysis  can  be  made. 


CHAPTER  XXV 

THE  AIR-FURNACE  AND  ITS  OPERATION 

INSTEAD  of  the  cupola,  the  air-furnace,  more  properly 
known  as  the  reverberatory  furnace,  is  used  for  melting  iron 
for  foundry  practice,  especially  where  malleable  castings  are 
to  be  made.  The  air-furnace  has  a  number  of  advantages 
over  the  cupola  and  also  certain  disadvantages.  These  ad- 
vantages may  be  summed  up  as  follows:  It  is  economical 
of  fuel,  can  be  cheaply  constructed  and  easily  repaired.  It 
may  be  started  at  any  time  from  the  cold  condition  and  can 
be  quickly  cooled  after  use.  It  requires  no  expensive  auxiliary 
machinery,  such  as  blowers,  gas  producers,  etc.  Its  principal 
disadvantage  is  that  it  consumes  a  greater  length  of  time  to 
melt  the  same  tonnage  than  the  other  forms  of  melting 
apparatus  and  the  metal  coming  out  of  it  at  the  end  of  a  heat 
is  liable  to  be  burned.  The  most  serious  disadvantage  is 
that  the  action  of  the  flame  in  the  furnace  is  such  as  to  notice- 
ably increase  the  sulphur  content  of  the  iron,  an  amount  of 
0.3  per  cent  frequently  being  added  when  the  coal  used  is 
high  in  sulphur.  Furthermore,  metal  cannot  be  long  held  in 
an  air-furnace  after  it  is  ready  for  pouring  unless  the  quality 
required  is  not  of  the  first  importance.  This  necessarily  limits 
the  size  of  the  furnace. 

The  illustrations,  Figs.  145-149,  show  a  typical  air-furnace. 
At  the  extreme  front  of  the  furnace  is  a  fire-box  G,  containing 
grate-bars  on  which  the  coal  for  melting  the  metal  is  burned. 
Behind  this  and  separated  from  it  by  a  bridge  wall  H,  is  the 
bath  or  hearth  A.  This  is  built  on  a  stone  foundation  over 
which  are  laid  two  courses  of  fire-brick,  these  being  covered 
with  a  thick  layer  of  silica  sand  to  form  the  hearth.  At  the 
rear  of  the  bath  is  another  wall  forming,  with  the  end  of  the 
furnace,  a  down-take  leading  to  a  flue  which  conveys  the  waste 
271 


272  FOUNDRY    PRACTICE 

gases  to  the  stack.  The  roof  of  the  furnace  over  the  fire-box 
is  of  arch  form  and  slants  downward  toward  the  bridge  wall 
as  shown.  The  roof  over  the  bath  is  formed  of  cast-iron  bungs 
constructed,  as  shown  in  Fig.  149,  of  iron  castings  with  the  tie 
rods  F  extending  across  them,  which  when  the  bung  is  lined 
with  fire-brick  are  tightened  to  hold  the  fire-brick  in  place. 
These  bungs  may  be  lifted  off  the  furnace  to  permit  charging, 
which  is  done  by  laying  the  iron  on  the  hearth.  Tapping 
spouts  are  provided  in  the  side  of  the  furnace,  as  are  also 
charging  doors  through  which  material  may  be  placed  in 
the  furnace  if  desired.  The  flames,  rising  from  the  fire  on 
the  grate-bars,  are  deflected  by  the  sloping  roof  so  that  they 
strike  and  play  upon  the  metal  in  the  hearth,  thus  melting  it 
down  to  a  liquid  for  pouring. 

The  hearth  is  composed  of  silica  sand  which  is  sintered 
before  the  furnace  is  put  in  operation.  Sand  is  rammed  down 
on  top  of  the  brick  to  a  depth  of  about  two  inches.  The 
bungs  are  then  put  in  place  and  the  furnace  fired  until  the  sand 
fuses  together.  When  the  first  layer  has  set  another  layer  is 
shoveled  in  and  the  operation  repeated,  the  process  continuing 
until  the  hearth  is  of  the  necessary  thickness,  which  ranges 
from  six  to  eight  inches.  The  hearth  must  be  so  formed  that 
the  iron  will  run  on  it  toward  the  tapping  spout.  If  this  is 
not  done  a  hoe  must  be  used  to  empty  all  pools  left  in  the  bot- 
tom when  the  furnace  is  drained.  A  good  mixture  of  sand 
for  the  hearth  is  two  parts  of  silica  sand,  with  a  silica  content 
of  95  per  cent  or  more,  to  one  part  of  ground  silica  rock. 

The  shape  of  the  hearth  is  important,  as  there  may  be 
a  thin  feather  of  metal  around  the  edge  of  the  hearth,  which 
may  become  badly  burned  during  the  course  of  operations. 
If  the  bottom  is  cut  away  to  a  certain  extent,  around  the  edge 
of  the  bath,  the  metal  may  then  be  given  a  thickness  of  two 
or  three  inches  at  this  point,  which,  in  connection  with  the 
slag  covering  it,  will  suffice  to  prevent  burning.  Three  spouts 
at  different  levels  are  recommended  by  Dr.  Moldenke  in 
order  that  the  iron  at  the  surface  of  the  bath  may  be  tapped 
first  and  burning  thereby  avoided. 


THE   AIR-FURNACE    AND    ITS    OPERATION 


273 


When  preparing  the  furnace  for  the  day's  heat,  the  bungs 
are  removed  and  the  furnace  thoroughly  cleaned  out.  If  the 
sand  below  the  hearth  has  been  injured,  it  is  re-formed  and 
repaired,  this  being  done  while  the  furnace  is  hot  so  that  the 
new  sand  will  bake  on  the  old.  The  hearth  is  then  made  up 


FIG.  147  PLAN 


FIQ.  146  SIDE  ELEVATION 


_      Stack 


SECTIONAL  ELEVATION 

FIGS.  145-149. — TYPICAL  AIR-FURNACE. 

with  a  mixture  of  fire-sand  and  red  clay.  Red  clay  should 
be  used  sparingly,  as  it  has  a  tendency  to  crack  in  drying,  per- 
mitting the  iron  to  flow  down  underneath  the  surface  and 
float  the  bottom  up.  In  charging  the  furnace,  sprues  are 
usually  placed  on  the  hearth  first,  being  spread  evenly  over 
the  bottom.  Over  them  the  pig-iron  is  piled,  half  the  charge 
18 


274  FOUNDRY    PRACTICE 

at  each  end  of  the  furnace.  This  method  of  charging  permits 
the  iron  to  melt  gradually,  which  would  not  occur  were  all  the 
metal  to  be  thrown  in  promiscuously  and  the  charge  would 
require  perhaps  an  hour  longer  to  melt  it. 

Westmoreland  County  (Pa.)  coal  is  advised  for  firing  an 
air-furnace.  The  best  practice  gives  about  four  pounds  of 
iron  melted  for  every  pound  of  fuel  burned. 

As  the  melting  proceeds,  test-plugs  are  made  by  pouring 
metal  into  the  molds,  formed  with  a  plug  one  inch  in  diameter. 
These  plugs  are  broken  and  the  fracture  examined.  If  there 
is  a  mottled  appearance  to  the  fracture  or  if  black  specks 
appear  in  it,  the  graphitic  carbon  is  too  high  and  must  be 
reduced  by  holding  the  metal  in  the  furnace  longer.  The 
mottled  appearance  indicates  that  the  silicon  in  the  metal 
in  the  furnace  is  too  high  or  that  the  temperature  of  the  furnace 
is  too  low.  The  charge  should  be  ready  for  pouring  about 
four  hours  after  charging  is  complete. 

The  principal  use  of  the  air-furnace  is  making  iron  for 
malleable  castings.  For  this  purpose  a  sharp,  white  iron  is 
required,  which,  after  casting,  is  annealed  in  proper  annealing 
ovens.  The  molding  of  malleable  castings  is  carried  on  in 
practically  the  same  manner  as  for  gray-iron  castings,  with 
the  exception  that  the  gating  is  so  arranged  that  the  mold  will 
fill  quickly,  as  white  iron  does  not  remain  fluid  as  long  as  gray 
iron.  Instead  of  providing  risers  over  heavy  portions  of  malle- 
able castings,  as  is  done  in  gray-iron  work,  a  chill  is  often  set 
against  the  heavy  part.  The  iron  cools  quickly  against  the 
chill,  and  the  light  and  heavy  portions  of  the  casting  cool  at 
about  the  same  time.  This  eliminates  strains  and  gives  a 
clean  sound  casting. 

The  subject  of  malleable  castings  is  too  wide  and  com- 
plicated to  be  treated  in  detail  in  a  book  of  this  character. 
The  reader  is  referred  to  "The  Production  of  Malleable 
Castings,"  *  by  Dr.  Richard  Moldenke,  which  is  the  most 
complete  work  on  this  subject  and  goes  into  every  detail  of 
malleable  practice. 

^he  Penton  Publishing  Co.,  Cleveland. 


CHAPTER  XXVI 

THE  BRASS  FOUNDRY 

CONNECTED  with  many  manufacturing  establishments  are 
brass  foundries  in  which  are  made  castings  from  the  non- 
ferrous  metals,  such  as  bronze,  brass,  aluminum,  etc.  The 
molding  operations  are  carried  on  in  practically  the  same  man- 
ner as  for  gray  iron,  finer  sand,  however,  being  used.  The 
metal  being  poured  at  a  lower  temperature  than  iron  does  not 
destroy  the  sand  as  iron  does.  The  larger  castings  in  brass 
are  molded  in  dry  sand  and  in  loam  exactly  as  is  done  for  iron. 
As  the  shrinkage  of  the  non-ferrous  metals  and  alloys  is  greater 
than  that  of  iron,  more  attention  must  be  given  to  provisions 
for  allowing  the  shrinkage  of  the  casting  in  the  mold  and  also 
larger  shrinkheads  'must  be  provided  than  is  usual  with  iron 
castings.  The  pouring  temperature  of  the  metal  has  an 
important  influence  on  the  character  of  the  finished  casting. 
Very  hot  metal  will  find  its  way  into  the  pores  of  the  sand  and 
produce  a  rough  casting.  The  temperature  at  pouring  should 
be  so  low  as  to  barely  permit  the  metal  to  flow  and  yet  produce 
a  smooth  casting.  This  temperature  in  turn  depends  largely 
on  the  composition  of  the  alloys. 

Instead  of  melting  in  a  cupola,  the  metal  in  the  brass 
foundry  is  melted  in  a  crucible  or  a  reverberatory  furnace,  the 
latter  using  coal,  coke,  oil,  or  gas  for  fuel.  The  crucibles  for 
melting  brass,  or  similar  non-ferrous  compositions,  are  made  of 
clay  and  graphite,  the  crucible  being  formed  and  then  baked 
to  calcine  the  clay.  Before  using,  the  crucibles  should  be 
seasoned  by  allowing  them  to  stand  in  a  warm  dry  place  for  a 
considerable  period,  after  which  they  are  gradually  heated  up 
to  a  temperature  of  255°  Fahr.  in  an  annealing  oven,  remaining 
in  the  oven  from  45  to  60  hours. 

In  Fig.  150  is  shown  one  of  the  older  types  of  coal-fired 
275 


276  FOUNDRY   PRACTICE 

crucible  furnace.  This  is  set  in  the  brick-pit  A ,  and  is  carried 
on  grate-bearers  as  shown.  The  coal  or  coke  is  placed  inside 
the  fire-brick  lining  and  the  crucible  E  bedded  in  it.  The 
furnace  is  set  with  its  top  practically  flush  with  the  floor  and 
it  is  connected  at  the  upper  end  with  a  flue  G.  In  commencing 


FIG.  150. — CRUCIBLE  BRASS  FURNACE. 

operations  with  this  furnace,  a  good  bed  of  coal  is  placed  on 
the  grate,  over  which  the  crucible  is  set  while  the  coal  is  being 
fired  in  order  that  it  may  heat  up  gradually.  Copper  ingots, 
or  ingots  of  other  metal  which  it  may  be  desired  to  melt,  are 
placed  in  the  crucible,  being  so  arranged  that  they  will  not 
wedge  with  each  other,  and  in  expanding  crack  the  crucible. 
After  the  copper  has  melted,  the  metal  requiring  the  next 
lower  degree  of  heat  is  added,  and  after  this  is  melted  the  other 


THE    BRASS    FOUNDRY  277 

metals  to  form  the  alloy  are  placed  in  the  crucible.  When 
the  mixture  is  entirely  melted,  the  crucible  is  lifted  from  the 
furnace  by  means  of  a  special  pair  of  tongs  which  encircle  the 
crucible  and  the  metal  is  skimmed  with  a  birch-rod  or  a 
wrought-iron  skimmer.  For  pouring,  the  crucibles  are  carried 
in  a  wrought-iron  shank  and  care  should  be  taken  that  the 


FIG.  151. — THE  OPEN-FLAME  FURNACE. 

crucible  be    completely  emptied  of    metal,  otherwise  it  will 
be  badly  damaged. 

In  place  of  the  coal-fired  crucible  furnace  just  described, 
open-flame  furnaces  illustrated  in  Fig.  151  are  in  wide  use.  Oil 
and  air  are  admitted  through  the  trunnions  at  a  pressure  of 
about  65  pounds  per  square  inch.  The  flame  from  the  oil 
plays  directly  on  the  metal  in  the  furnace.  Open-flame  fur- 
naces have  the  disadvantage  of  causing  large  losses  of  metal 
through  oxidation  unless  great  care  is  taken  in  the  control  of 
the  furnaces.  A  further  development  of  the  oil-  or  gas-fired 
furnace  is  shown  in  Fig.  152.  This  furnace  is  known  as  the 
crucible-tilting  furnace,  the  metal  being  melted  in  a  crucible 
set  in  the  fire-brick  chamber  forming  the  furnace  proper  and 


278 


FOUNDRY    PRACTICE 


flames  from  the  oil  or  gas  playing  around  the  furnace  as 
shown.  The  metal  is  thus  protected  from  the  oxidizing  effect 
of  the  flame,  and  the  melting  loss,  with  proper  regulation  of 
the  furnace,  is  low. 

The  pouring  temperature  of  alloys  used  in  the  brass  foundry 
being  low,  the  metal  should  be  poured  in  the  molds  as  promptly 
as  possible  after  melting.  The  castings,  on  removal  from  the 
sand,  are  cleaned  by  pickling. 

The  brass  foundry  requires  a  book  in  itself  for  its  proper 


FIG.  152.— THE  CRUCIBLE-TILTING  FURNACE. 

treatment.  No  small  part  of  such  a  book  would  be  given  over 
to  the  composition  of  alloys  and  the  mixtures  for  making  them. 
Every  brass  founder  has  his  own  ideas  on  these  mixtures  and 
their  number  is  legion.  The  writer  has  successfully  used  the 
mixtures  given  below  for  the  purposes  mentioned.  For  a  very 
complete  treatise  on  this  subject  see  "Practical  Alloying,"1 

'The  Penton  Publishing  Co.,  Cleveland. 


THE   BRASS   FOUNDRY  279 

by  J.  F.  Buchanan.  See  also  tables  in  the  Appendix,  pages 
315  to  317. 

Alloy  for  stationary  engine  work:  ingot  copper,  9  pounds; 
tin,  i  pound;  zinc,  I  ounce. 

Composition  for  heavy  work:  ingot  copper,  46  pounds; 
tin,  7  pounds;  spelter,  3  pounds;  lead,  iH  ounces. 

A  tough  yellow  metal:  copper,  12  pounds;  spelter,  4 
pounds;  lead,  ^  pound;  tin,  ^4  pound. 

Another  yellow  metal :  copper,  20  pounds ;  zinc,  8  pounds ; 
lead,  i  pound. 

Babbitt  metal  for  heavy  bearings:  copper,  2  pounds; 
antimony,  2  pounds;  tin,  72  pounds. 

Hardening  metal  for  heavy  bearings :  tin,  2  pounds;  used 
with  i  pound  of  a  mixture  of  the  following  proportion :  copper, 
12;  antimony,  24;  tin,  27. 

A  hard  bronze:  copper,  88;  tin,  6;  zinc,  4;  lead,  2;  phos- 
phor-tin, 2. 

Gun-metal:  copper,  44;   tin,  4;  lead,  i;  phosphor-tin,  i. 

Gun-metal:  copper,  88;  tin,  8;  zinc,  4;  lead,  2. 

Phosphor-bronze:  copper,  88;  tin,  7;  zinc,  4;  lead,  2; 
phosphor-tin,  i. 

Phosphor-bronze,  medium  hardened:  copper,  100;  zinc, 
12;  tin,  4;  lead,  i^. 

Yellow  brass:  copper,  4;  zinc,  i;  lead,  fa. 


CHAPTER   XXVII 

FOUNDRY  EQUIPMENT 

Ladles. — A  variety  of  ladles  for  transferring  the  molten 
iron  from  the  melting  furnace  to  the  molds  is  used  in  the  foun- 
dry, ranging  in  size  from  the  small  hand-ladle  holding  twenty- 
five  pounds  of  iron  to  ladles  containing  as  much  as  fifty  tons 
which  are  used  in  steel  and  heavy  iron  foundries  and  are 
handled  by  the  crane.  Smaller  ladles  are  made  of  cast-iron 
with  lugs  to  which  handles  are  fitted,  while  the  larger  ones 
are  constructed  of  steel  plates  riveted  together  and  provided 
with  trunnions  by  means  of  which  they  are  suspended  from  the 
crane.  The  ladles  of  all  sizes  are  lined  with  fire-clay  of  the 
same  grade  as  is  used  to  line  the  cupola  to  protect  the  bottom 
and  sides  from  the  molten  iron.  The  smaller  hand-ladles  are 
of  such  size  that  they  may  be  carried  by  a  single  molder  and  are 
used  for  pouring  the  lighter  castings  made  in  bench  molds  and 
also  for  feeding  risers  and  shrinkheads  in  castings  which 
require  churning  or  pumping.  The  next  larger  size  of  ladle 
is  known  as  the  double-shank  ladle  and  is  carried  and  poured 
by  two  men.  Larger  ladles  than  these  are  used  either  for 
pouring  heavy  castings  or  for  transporting  large  amounts  of 
iron  to  central  points  in  the  foundry  whence  the  iron  is  con- 
veyed in  hand  or  double-shank  ladles  to  the  molds.  These 
ladles  are  handled  by  means  of  tramways  or  cranes.  The 
largest-size  ladles  holding  upward  of  one  ton  are  handled 
exclusively  by  cranes  and  are  usually  lined  with  fire-brick 
ever  which  fire-clay  is  daubed.  Before  using,  the  ladle  should 
be  thoroughly  dried  and  heated  either  by  means  of  an.  oil- 
torch  or  a  fire  built  in  it.  Any  moisture  in  the  lining  will 
become  steam  when  the  molten  metal  is  poured  into  it,  and 
start  an  agitation  in  the  metal  which  may  seriously  damage 
the  lining  and  permit  the  molten  metal  to  come  in  contact  with 
280 


FOUNDRY   EQUIPMENT  28 1 

the  metal  of  the  ladle,  thus  burning  a  hole  through  it  and  allow- 
ing the  molten  metal  to  escape  and  do  serious  damage.  Most 
ladles  used  in  the  foundry  pour  over  the  lip,  but  for  steel 
castings  an  opening  is  provided  in  the  bottom  of  the  ladle, 
closed  by  a  suitable  plug  which  is  removed  when  the  mold  is 
to  be  poured  and  the  steel  is  taken  from  the  bottom  of  the 
ladle.  Occasionally  the  lip  of  the  ladle  is  made  higher  than  the 
rest  of  the  rim  and  a  hole  is  cut  through  it  through  which  the 
iron  is  poured.  The  lip  thus  acts  as  a  skimmer  and  prevents 
slag  from  flowing  with  the  iron  into  the  mold.  When  filling 
large  ladles  the  iron  is  covered  with  charcoal  or  some  refractory 
material  to  exclude  the  air  and  thus  prevent  oxidation. 

Flasks. — Flasks  for  use  in  the  foundry  are  made  either  of 
iron  or  wood.  Wooden  flasks  should  be  made  of  substantial 
material,  as  they  are  liable  to  burning  and  in  a  short  time  if 
made  too  light  will  be  completely  burned  away  at  the  joint 
and  run-outs  of  the  mold  will  be  frequent.  For  very  heavy 
castings,  iron  flasks  are  more  generally  used  and  these  are 
made  so  far  as  possible  so  that  the  different  parts  will  be 
interchangeable  with  one  another.  Thus  the  pin-holes  are 
bored  in  the  flanges  to  a  template  and  the  pins  are  located  by 
the  same  template.  Thus  any  number  of  flasks  of  the  same 
size  can  be  piled  one  on  the  other  to  form  cheeks  and  copes. 
The  ends  are  usually  made  so  that  different  flasks  can  be 
butted  one  to  another  and  a  long  flask  thus  formed.  For 
side-floor  work,  the  flasks  are  usually  made  to  conform  to  the 
shape  of  the  pattern,  thus  diminishing  the  amount  of  sand 
rammed  in  the  flask  and  making  it  lighter  for  the  molder  to 
handle.  Large  iron  flasks  should  be  provided  with  slotted 
holes  in  the  sides  through  which  bolts  may  be  passed  to  hold 
bars  in  place.  By  this  means  the  bars  can  be  arranged  as 
desired  to  suit  the  necessities  of  the  pattern  in  hand.  Iron 
flasks  should  be  made  sufficiently  heavy  to  prevent  springing 
under  the  pressure  of  the  metal  in  the  mold.  It  is  a  mistaken 
idea  that  because  a  flask  is  of  iron  there  is  no  spring  to  it. 
However,  it  is  not  necessary  to  make  the  sides  of  the  flask  of 
uniform  thickness  to  resist  the  tendency  to  spring;  ribs  cast 


282  FOUNDRY   PRACTICE 

on  the  sides  will  serve  the  purpose  just  as  well  and  make  a 
lighter  construction.  Trunnions  should  be  made  preferably 
of  steel  cast  into  the  sides  of  the  flask  rather  than  of  cast-iron 
cast  in  one  piece  with  the  flask.  The  flask  should  always  be 
of  such  size  that  there  is  ample  sand  between  it  and  the  pat- 
tern, not  only  to  protect  the  flask  from  the  molten  iron,  but 
to  absorb  the  gases  given  off  in  pouring.  In  many  cases  when 
iron  flasks  are  made,  lugs  are  arranged  on  each  end  of  the  cope 
and  drag  so  that  they  will  come  in  line  with  each  other.  Holes 
are  bored  in  these  lugs  and  a  rod  run  through  them  to  form 
a  guide  for  lifting  the  cope  over  high  parts  of  the  pattern. 
Steel  flasks  are  coming  into  use,  being  light  and  serviceable, 
but  on  account  of  their  lightness  they  heat  rapidly  and  may 
warp  out  of  shape,  in  which  case  it  is  difficult  to  restore  them 
to  their  original  form.  I-beams  are  also  frequently  used  to 
form  the  sides  of  the  flask.  Flasks  for  molding-machine  work 
are  frequently  of  iron,  although  for  small  castings  the  wooden 
snap  flasks,  of  which  there  are  a  number  of  varieties  on  the 
market,  are  in  general  use.  It  is  advisable  to  plane  the  edges 
of  iron  flasks  where  good  work  is  expected  and  the  pins  should 
be  carefully  fitted. 

Tumbling  Barrels. — Tumbling  barrels  are  made  in  a 
variety  of  shapes  and  sizes.  The  square  tumbling  barrel,  or 
rattler,  is  convenient  for  a  number  of  varieties  of  castings  and 
is  often  made  of  cast-iron  with  cast-iron  heads  and  provided 
with  cast-iron  stays  extending  from  end  to  end.  Rattlers 
are  often  made  with  the  sides  in  sixteen  or  more  segments, 
any  one  of  which  may  be  replaced  when  worn  out  or  broken. 
They  are  often  combined  with  a  sand-blast  arrangement 
whereby  sand  is  blown  under  air  pressure  into  the  rattler 
through  one  of  the  trunnions  to  assist  in  cleaning  the  casting. 
Often  rattlers  are  made  with  wooden  staves  supported  by  iron 
stays  on  the  outside,  or  the  iron  rattler  may  be  lined  with 
wood.  Exhaust-pipes  should  be  connected  to  each  rattler 
through  which  a  fan  may  remove  the  dust  incident  to  their 
use.  A  very  popular  form  of  tumbling  barrel  for  small  -cast- 
ings is  the  open  tilting  tumbling  barrel,  which  may  be  tilted 


FOUNDRY   EQUIPMENT 


283 


FIG.  153. — FOUNDRY  RIGS. 


284  FOUNDRY   PRACTICE 

to  discharge  the  tumbled  castings  and  elevated  to  an  inclined 
position  for  rattling.  A  stream  of  water  is  directed  into  this 
barrel  while  in  use  in  order  to  prevent  dust. 

Cranes. — Up  to  comparatively  recent  times,  the  jib-crane 
operated  by  a  hand-winch  was  almost  exclusively  used  in  iron- 
foundries.  These  were  extremely  limited  in  their  application 
and  were  useless  beyond  a  circle  of  which  the  crane  arm  formed 
the  radius.  In  the  more  modern  foundries  they  have  been 
largely  displaced  by  the  traveling  crane,  either  hand  or 
electric,  depending  on  the  weight  and  amount  of  work  done. 
The  most  important  feature  in  an  electric  crane  for  foundry 
use,  aside  from  its  ability  to  carry  the  maximum  weight  of 
casting  made  in  the  foundry,  is  its  control  apparatus.  This 
must  be  such  as  to  permit  very  gradual  starting  and  stopping, 
and  of  operation  at  extremely  low  speeds.  In  drawing  large 
patterns  from  the  molds  by  means  of  the  crane,  they  must  be 
started  gradually  and  slowly.  Too  quick  a  start  will  break 
the  mold.  Also,  in  rolling  over  copes  of  large  sizes,  a  sudden 
start  will  shake  the  sand  out  of  the  mold  and,  in  lifting,  the 
operator  must  be  able  to  stop  the  crane  the  moment  that  the 
cope  is  vertical  and  before  it  has  swung  clear  of  its  support 
on  the  opposite  edge.  Furthermore,  exact  control  must  be 
maintained  over  the  crane  when  pouring  castings  from  a 
crane  ladle.  The  molder  must  be  able  to  tilt  the  ladle 
continuously  to  maintain  a  uniform  stream  of  iron  into  the 
mold  and  to  stop  instantly  when  the  mold  is  full.  This 
requires  the  co-operation  of  the  crane  operator.  Instead  of 
cranes,  traveling  electric  hoists  may  be  used  and  the  same 
considerations  apply  to  them  as  to  cranes.  It  would  be  out 
of  place  here  to  discuss  the  relative  features  of  different  cranes 
and  the  reader  is  referred  to  the  catalogues  of  manufacturers 
for  such  information. 

Foundry  Rigs. — The  foundry  requires  a  miscellaneous 
equipment  of  small  rigging  for  handling  flasks,  ladles,  etc., 
for  setting  cores  and  securing  molds  for  pouring.  A  variety 
of  this  equipment  is  illustrated  in  Figs.  153  and  154.  A  is 
a  yoke  and  B  is  one  of  the  slings  used  with  it  for  handling  copes 


FOUNDRY   EQUIPMENT 


285 


o 


\  /  / 

\       b/i        f 

V  j  l  1 


END  VIEW.  OF 
REVOLVING  GAGGER  BOARD 


FIG.  154. — FOUNDRY  RIGS. 


286  FOUNDRY    PRACTICE 

and  drags  by  means  of  the  crane.  The  yoke  is  made  of  a  solid 
timber  suspended  at  the  center  by  means  of  iron  straps  and  an 
eye.  Occasionally  the  yoke  is  made  of  iron  or  a  section  of  an 
I-beam.  Instead  of  the  yoke,  the  spreader  C  is  used  in  con- 
nection with  a  double  strand  chain  which  is  hooked  on  to  the 
trunnions  of  a  flask,  the  spreader  being  placed  above  the  flask 
at  the  right  height  with  the  chain  links  in  the  slots  of  the 
spreader.  If  trunnions  are  not  cast  on  the  flask,  loose  trun- 
nions D  may  be  bolted  to  it.  These  may  be  used  with 
wooden  or  iron  flasks.  The  casting  E  is  usually  bolted  to 
the  sides  of  the  cope  to  permit  chains  to  be  hooked  to  it  for 
hoisting  the  cope  off  and  to  act  as  rockers  on  which  the  flask 
may  be  rolled  over  after  it  has  been  set  on  the  floor.  F  is  a 
form  of  staple  which  is  frequently  bolted  to  the  flask  for  the 
purpose  of  accommodating  crane  chains,  while  G  is  a  similar 
staple  made  of  steel  around  which  an  iron  plate  is  cast.  H 
is  a  hook  bolted  to  the  sides  of  a  cope  on  which  the  crane 
chains  are  fastened  when  only  a  straight  lift  is  desired.  / 
is  a  loop  forged  from  steel,  usually  made  in  sets  of  four,  to 
place  over  each  handle  of  a  cope,  when  it  is  necessary  to  lift 
it  by  means  of  a  crane  and  it  is  not  desired  to  use  any  of  the 
attachments  previously  noted.  These  loops  are  frequently 
used  to  slip  over  the  arbors  of  cores  when  the  latter  project 
beyond  the  mold,  and  form  a  very  convenient  means  of 
handling  such  cores.  /  is  a  convenient  roller  for  nailing  to 
the  side  of  a  wooden  flask  to  act  as  a  rocker  in  rolling  it  over. 
K  is  a  convenient  S-hook  for  handling  copes,  connecting  short 
chains,  setting  cores,  and  removing  castings  from  the  molds. 
L  is  a  core-hook  for  setting  cores,  and  may  be  made  in  many 
styles  and  sizes.  Chains  should  be  made  with  a  link  large 
enough  to  take  the  hook  of  the  chain,  set  back  a  certain  dis- 
tance from  the  end.  The  chain  can  then  be  doubled  back  on 
itself  with  the  hook  in  this  link  and  used  as  a  sling.  In 
handling  medium-sized  work,  one  or  two  chains  having 
turnbuckles  in  them  will  save  considerable  time  in  adjusting 
for  any  given  lift. 

Straight-edges  of  various  lengths  with  holes  bored  in  them 


FOUNDRY   EQUIPMENT  287 

so  that  they  can  be  hung  up  when  not  in  use  are  serviceable 
tools  to  have  in  the  foundry.  A  gagger-board  is  a  useful  piece 
of  equipment  for  molding  gaggers.  A  bed  of  molding  sand  is 
spread  as  nearly  level  as  possible  and  the  gaggers  arranged 
on  a  board  are  pressed  down  into  this  bed  and  the  board 
leveled  with  a  spirit-level.  On  lifting  the  board  a  series  of 
gagger-molds  are  left  in  the  sand,  which  may  be  filled  with 
molten  iron  and  the  gaggers  formed.  In  Fig.  154  a  revolving 
gagger-board  is  shown  at  M.  The  drum  is  molded  plain  and 
slab-cores  forming  the  gagger-molds  are  set  on  the  faces.  As 
fast  as  one  side  is  poured  the  drum  is  revolved  and  the  next 
side  brought  to  the  top  and  poured.  N  is  an  ingot  mold  with- 
out a  bottom  in  which  slack  iron  from  the  hand-ladles  is 
poured.  It  is  set  in  loose  sand,  placed  on  the  floor,  and  when 
filled  with  slack  iron  is  picked  up  and  moved  to  a  new  loca- 
tion. 0  is  a  larger  ingot  mold  for  receiving  slack  iron  and 
also  the  iron  from  the  cupola  at  the  end  of  the  heat.  P  is  a 
cross  used  for  hoisting  portions  of  a  mold  such  as  the  center 
of  the  loam  mold  described  in  Chapter  XI,  and  Q  is  one  of 
four  slings  used  with  this  cross.  R  is  a  finger  for  attaching 
sweeps  to  a  spindle,  and  6"  is  a  straight-edge  used  by  loam 
molders,  the  notch  in  the  center  being  fitted  around  the 
spindle. 


GLOSSARY 

AIR-FURNACE — A  furnace  for  melting  iron,  principally  used 
in  malleable  practice;  see  reverberatory  furnace. 

ARBOR — A  bar  or  mandrel  used  as  the  center  on  which  is 
built  up  a  core. 

ANNEAL — To  soften  or  render  ductile  a  casting  by  the  applica- 
tion of  heat  in  connection  with  a  carbonaceous  material 
packed  around  it.  The  final  process  in  malleable  work. 

BAKED  CORE — A  dry-sand  core  which  has  been  subjected  to 
heat,  usually  in  an  oven,  to  render  it  hard  and  to  fix  its 
shape:  the  opposite  of  green  core. 

BARS — Ribs  placed  across  the  cope  portion  of  a  flask. 

BASIN — The  portion  of  a  cupola  below  the  tuyeres  in  which 
the  molten  iron  collects. 

BATH — The  iron  on  the  hearth  of  an  air-furnace. 

BEAD  SLICKER — A  tool  for  finishing  a  hollow  place  in  a  mold. 

BED  CHARGE — The  first  coke  charged  into  a  cupola. 

BELLOWS — An  ordinary  small  bellows  used  for  blowing  sand 
from  the  joint  of  a  mold,  and  for  blowing  it  from  deep 
pockets  in  the  mold. 

BENCH — The  framework  table  at  which  small  molds  are  made. 

BENCH  WORK — Molds  of  such  small  size  that  they  can  be 
made  at  the  molder's  bench. 

BINDER — A  bar  of  wood  or  iron,  with  slotted  ends  to  receive 
bolts,  placed  across  a  cope  to  hold  the  cope  on  the  drag. 

BLACK  SAND — Heap  sand. 

BLAST — The  supply  of  air  to  a  cupola. 

BOD — A  ball  of  clay  for  closing  the  tap-hole. 

BOSH — See  swab. 

BOTTOM-BOARD — A  board  placed  on  the  under  side  of  a  mold. 

BREAK-OUT — A  rupture  of  a  mold  permitting  metal  to  flow 
out  at  the  joint.     Also  called  run-out. 
288 


GLOSSARY  289 

BREAST — The  portion  of  the  lining  of  a  cupola  immediately 
surrounding  the  tap-hole. 

BRICKS,  FIRE — Bricks  made  of  fire-clay  used  for  cupola  and 
air-furnace  lining. 

BRICKS,  LOAM — Bricks  formed  of  a  loam  mixture,  to  set  in  a 
mold  and  to  permit  the  easy  crushing  of  the  mold  under 
the  shrinkage  of  the  casting. 

BRUSH — A  brush  used  for  sweeping  sand  from  the  joint  of 
molds. 

BUCKLES — Swellings  in  the  surface  of  a  mold  due  to  the  genera- 
tion of  steam,  below  the  surface,  which  cannot  escape. 

BUNG — A  section  of  roof  of  an  air-furnace. 

BUTT — The  large  round  end  of  a  rammer. 

CALIPERS — A  measuring  tool  for  ascertaining  the  outside 
diameter  of  cylindrical  bodies. 

CAMEL'S-HAIR  BRUSH — A  brush  for  applying  blacking  to  the 
surface  of  molds. 

CARRYING  PLATES — Iron  plates  used  to  support  certain  por- 
tions of  loam  molds. 

CASTING — The  product  of  the  foundry  obtained  by  pouring 
molten  metal  into  a  mold. 

CEMENTITE — The  constituent  of  commercial  iron  consisting 
of  iron  chemically  combined  with  carbon. 

CHAPLET — A  piece  of  metal,  shaped  in  various  ways,  placed  in 
a  mold  to  support  a  core. 

CHARGE — The  iron  and  fuel  placed  in  a  cupola  or  air-furnace. 

CHARGING  DOOR — The  opening  in  a  cupola  or  air-furnace 
through  which  fuel  and  metal  are  introduced. 

CHEEK — The  portion  of  a  mold,  made  in  three  parts,  inter- 
mediate between  the  cope  and  drag. 

CHILL — An  iron  surface,  sometimes  water-cooled,  of  a  mold, 
used  to  chill  the  molten  iron  rapidly  and  thus  produce  a 
hard  surface  on  the  casting. 

CHILLED  WORK — Castings  made  in  a  chill  mold. 

CHUCK — Small  bars  set  between  the  cross  bars  of  a  flask. 

CHURNING — See  pumping. 

CLAMPING  BAR — A  bar  used  to  tighten  clamps  on  a  flask. 
19 


690  GLOSSARY 

CLAMPS — Devices  for  fastening  copes  and  drags  together. 

CLAYWASH — A  wash  formed  of  clay  dissolved  in  water. 

COLD  SHUT — An  imperfection  in  a  casting  due  to  the  metal 
entering  the  mold  by  different  sprues,  and  cooling,  fail- 
ing to  unite  on  meeting. 

COPE — The  upper  half  of  a  mold. 

COPE  DOWN — To  build  projecting  bodies  of  sand  on  the  sur- 
face of  the  cope  to  form  surfaces  of  the  casting  which  are 
below  the  level  of  the  joint  of  the  drag. 

COPE  PLATE — An  iron  plate  used  to  support  certain  portions 
of  loam  molds. 

CORE — A  body  of  sand,  either  green  or  dry,  placed  in  a  mold 
to  form  a  cavity  in  the  casting. 

CORE  Box — A  box  in  which  cores  are  formed. 

CORE  PLATE — A  flat  iron  plate  on  which  green  cores  are  placed 
for  baking. 

CORE-PRINT — The  cavity  in  a  mold  in  which  the  ends  of  cores 
are  set.  Also  the  projections  on  a  pattern  which  form 
and  locate  the  prints  in  the  mold. 

CORNER  TOOL — A  tool  for  slicking  the  corner  of  a  mold,  in- 
accessible to  the  ordinary  form  of  finishing  tools. 

CRUCIBLE  ZONE — The  basin  of  a  cupola. 

CUPOLA — A  shaft  furnace  for  the  melting  of  iron ;  the  iron 
and  fuel  being  charged  in  alternate  layers,  and  com- 
bustion promoted  by  air  blown  in  at  the  bottom  of 
the  furnace. 

DOUBLE-ENDER — A  molding  tool  consisting  of  a  combined 
slicker  and  spoon-slicker. 

DRAFT — The  taper  given  to  the  sides  of  a  pattern  to  enable 
it  to  be  easily  withdrawn  from  the  mold. 

DRAG — The  lower  half  of  the  mold. 

DRAWING  THE  PATTERN — Lifting  a  pattern  from  the  sand  of  a 
completed  mold. 

DRAW-NAIL — A  pointed  rod  of  iron  or  steel  driven  into  a 
wooden  pattern  to  act  as  a  handle  to  withdraw  it  from  the 
sand  in  a  mold. 

DRAWPEG — A  draw-screw. 


GLOSSARY  291 

DRAW-SCREW — A  rod  screwed  into  a  pattern  to  act  as  a  handle 

for  drawing  the  pattern. 
DRAW-SPIKE — See  draw-nail. 
DRYER — A  metal  form,  of  the  same  shape  as  a  core,  in  which 

the  latter  is  placed  while  being  baked. 
DRY  SAND — Sand  which  has  been  baked  in  an  oven  after 

having  been  formed  into  a  mold. 
DRY-SAND  MOLD — A  mold  which  has  been  baked  in  an  oven 

to  fix  its   shape   permanently,    and    to   give   it  a  hard 

surface. 
EARS — The  lugs  on  the  cope  part  of  a  flask  into  which  the  pins 

on  the  drag  fit. 

EYE-BOLT — A  bolt  with  a  ring  welded  at  one  end. 
FALSE  CHEEK — A  body  of  sand  in  a  mold,  occupying  the  same 

position  and  performing  the  same  functions  as  a  cheek, 

but  contained  within  the  cope  and  drag,  although  separate 

from  it. 

FEEDING-HEAD — See  shrinkhead. 
FERRITE — The  constituent  of  commercial  iron  consisting  of 

pure  iron.     See  cementite. 
FIRE-BRICK — See  bricks,  fire. 
FLANGE  TOOL — A  tool  for  furnishing  the  edges  of  flanges  in  a 

mold. 
FLASK — The  frame-work  of  wood  or  iron  in  which  the  sand  is 

packed  while  being  molded  around  a  pattern. 
FLAT-BACK — A  pattern  with  a  flat  surface  at  the  joint  of  the 

mold.     Thus  a  flat-back  pattern  lies  wholly  within  the 

drag  and  the  joint  of  the  cope  is  a  plane  surface. 
FLAT  GATE — A  wide  gate  with  a  narrow  opening  into  the 

mold,  used  for  pouring  thin  flat  castings.     See  Fig.  129. 
FLOOR  MOLDING — See  floor  work. 
FLOOR  WORK — Molds  large  enough  to  require  molding  on  the 

floor  of  the  foundry. 
FLOW-OFF — A  channel  cut  from  a  riser  to   permit  metal  to 

flow  away  from  it  when  it  has  risen  in  the  riser  to  a  certain 

predetermined  height. 
FLUX — A  fusible  material,  containing  lime,  such  as  limestone, 


2Q2  GLOSSARY 

charged  in  the  melting  furnace  to  combine  chemically  with 
and  carry  off  impurities  from  the  molten  metal. 

FOUNDRY — A  shop  where  castings  are  made. 

FROZEN  IRON — Iron  which  has  solidified. 

GAGGERS — Rods  of  wrought-  or  cast-iron,  with  one  end  bent 
at  a  right  angle,  used  to  support  hanging  bodies  of  sand 
in  a  mold. 

GATE — The  hole  in  the  cope  through  which  metal  is  poured 
into  the  mold. 

GATE-STICK — A  stick  set  in  the  cope  while  it  is  being  rammed 
to  form  the  passage  into  the  mold  through  which  the 
molten  metal  is  poured. 

GATING  PATTERNS — Arranging  patterns  on  a  backbone  so  that 
sprues  will  be  formed  by  the  backbone  and  its  connection 
to  the  pattern  when  the  mold  is  made. 

GREEN  CORE — A  core  which  has  not  been  baked. 

GREEN  SAND — Ordinary  molding  sand  which  has  not  been 
baked  or  otherwise  been  subjected  to  heat  treatment,  ex- 
cept by  coming  in  contact  with  molten  metal  in  the  mold. 

GREEN-SAND  CORE — A  core  made  of  green  sand. 

GREEN-SAND  MATCH — A  false  cope  in  which  the  patterns  are 
placed  while  the  drag  is  being  made.  Its  object  is  to  avoid 
the  making  of  a  difficult  joint  on  each  mold  where  there 
are  a  number  of  castings  to  be  made  from  one  pattern. 

GRID — See  skeleton. 

HAND  SQUEEZER — A  molding  machine  in  which  the  sand  is 
compressed  to  the  proper  density  by  pressure  applied  by 
hand  to  the  outer  surface  of  the  mold. 

HAY-ROPE — A  rope  made  of  twisted  hay,  used  to  form  the 
basis  of  cores  made  on  arbors. 

HEAP  SAND — Green  sand  from  the  foundry  floor. 

HEARTH — That  portion  of  an  air-furnace  on  which  the  iron  is 
melted. 

HEAT — The  melting  period  of  a  cupola  or  air-furnace. 

HORN  GATE — A  semicircular  gate  to  convey  iron  over  or 
under  certain  parts  of  a  casting,  so  that  it  will  enter  the 
mold  at  or  near  the  center.  Also  used  as  a  skim  gate. 


GLOSSARY  293 

HUB  TOOL — A  tool  for  finishing  the  mold  of  pulley  hubs. 
JARRING  MACHINE — A  molding  machine  in  which  the  sand  is 

packed  by  the  sand,  pattern,  and  flask  being  raised  and 

dropped  upon  a  table,  the  sand  itself  forming  the  ramming 

medium. 
JOINT — The  portion  of  the  mold  where  the  cope  and  drag  come 

together — the  upper  surface  of  the  drag  and  the  lower 

surface  of  the  cope. 
JOLT-RAMMER — See  jarring  machine. 
LIFTER — A  molder's  tool  with  a  flat  end  at  right  angles  to  the 

stem,  used  to  lift  loose  sand  from  deep  pockets  in  the  mold. 
LOAM — A  mixture  of  molding  sand  and  clay  used  for  making 

loam  molds.     See  Chapter  XL 
LOAM  BRICKS — See  bricks,  loam. 
LOAM  MOLD — A  mold  built  up  of  brick-work,  iron  plates,  etc., 

covered  with  loam  which  is  afterward  baked  on. 
MACHINE  MOLDING — The  operation  of  making  molds  on  a 

molding  machine. 
MALLEABLE  CASTING — A  hard  brittle  casting  of  white  iron, 

which  is  rendered  tough  and  malleable  by  annealing  under 

certain  conditions. 
MELTING  ZONE — The  portion  of  the  cupola  above  the  tuyere 

zone  in  which  the  iron  is  fused. 
MOLD — The  formed  cavity  in  sand  or  other  material  into 

which  molten  iron  is  poured  to  obtain  a  casting  of  any 

desired  shape.     The  term  is  usually  applied  to  the  body 

of  sand  surrounding  the  cavity. 
MOLD-BOARD — The  board  on  which  the  patterns  are  laid  when 

making  the  drag  of  a  mold. 
MOLDING  MACHINE — A  machine,  operated  either  by  hand  or 

power,  for  making  molds. 
MOLDING  SAND — Sand  suitable  for  forming  into  molds.     See 

Chapter  XXII. 
NOWEL — See  drag. 
PARAFFINE-BOARD — A  board  impregnated  with  paraffine  on 

which  patterns  are   mounted    for  use  on   the  molding 

machine. 


294  GLOSSARY 

PARTING — The  plane  on  which  a  pattern  is  split. 

PARTING  SAND — A  fine,  sharp,  dry  sand  dusted  on  the  joint 

of  a  mold  to  prevent  the  cope  and  drag  adhering  to  each 

other. 
PATTERN — The  object  of  wood,  metal,  or  other  material  whose 

shape  it  is  desired  to  reproduce  in  metal.     The  sand    of 

the  mold  is  formed  around  the  pattern,  which  is  later 

withdrawn,  leaving  a  cavity  of  its  exact  size  and  shape  to 

be  filled  with  molten  metal. 
PEEN — The  flat-pointed  end  of  a  rammer.     Also,  the  operation 

of  ramming  with  the  peen  end  of  a  rammer,  as  peening  the 

sand. 
PEG  GATE — A  round  gate  leading  from  a  pouring  basin  in 

the  cope  to  a  basin  in  the  drag,  whence  sprues  lead   to 

the  mold.    See  Fig.  129. 
PINS — The  projections  on  the  drag  of  a  flask  which  guide  and 

hold  it  in  position  with  relation  to  the  cope. 
PIPE  TOOL — A  tool  for  finishing  the  surface  of  pipe  molds. 
POURING  BASIN — A  basin  formed  in  the  cope  into  which  the 

iron  is  poured. 
POWER  SQUEEZER — A  molding  machine  in  which  the  sand  is 

compressed  to  the  proper  density  by  pressure,  applied 

by  compressed  air  to  the  outer  surface  of  the  mold. 
PUMPING — The  action  of  feeding  iron  to  a  casting  from  a 

shrinkhead   by  forcing  it  in  with  a  rod  moved  up  and 

down  in  the  shrinkhead. 
RAMMER — The  tool  used  by  the  molder  for  packing  sand  in  a 

flask  around  a  pattern.     They  are  made  of  wood  in  the 

smaller  sizes,  known  as  hand  rammers,  and  of  iron  in  the 

larger  sizes. 
RAMMING — The  action  of  packing  sand  around  a  pattern  in  a 

flask  to  form  a  mold. 
RAPPING — The  action  of  jarring  a  pattern  in  the  sand  to  free 

it  so  that  it  may  be  drawn  from  the  mold. 
RAPPING  IRON — An  iron  bar  used  to  strike  the  draw-nail  in 

order  to  jar  the  pattern  preparatory  to  drawing. 
REVERBERATORY  FURNACE — A  furnace  for  the  melting  of  iron, 


GLOSSARY  295 

the  iron  and  fuel  being  separated.  The  fuel  is  burned  in 
a  fire-box,  separated  from  the  iron  on  a  hearth  by  a  bridge 
wall.  A  sloping  roof  deflects  the  gases  of  combustion 
down  on  the  iron  and  thus  melts  it.  Largely  used  in 
malleable  work. 

RIDDLE — A  sieve  for  sifting  sand  on  a  pattern. 

RISER — A  gate  formed  over  a  high  portion  of  a  mold  to  act  as 
an  indicator  when  the  mold  is  filled  with  metal,  and  also 
to  act  as  a  feeder  to  supply  iron  to  the  casting  as  it  shrinks 
in  passing  from  the  liquid  to  the  solid  state. 

ROLL-OVER  MACHINE — A  molding  machine  in  which  the  mold 
is  rolled  over  before  the  pattern  is  drawn. 

RUNNER — A  deep  channel  formed  in  the  top  of  a  cope,  connect- 
ing with  gates,  into  which  the  molten  metal  is  poured. 

RUNNER  Box — A  set-off  box  in  which  a  runner  is  formed. 

RUN-OUT — See  break-out. 

SCABS — Imperfections  in  a  casting  due  to  portions  of  the  sur- 
face of  a  mold  breaking  away. 

SET  GATE — A  gate  pattern  used  to  form  a  gate  or  sprue,  set 
against  the  pattern. 

SET-OFF  Box — A  small  box,  open  at  the  top  and  bottom, 
fastened  to  the  top  of  a  cope  to  contain  portions  of  a 
mold  projecting  above  the  cope. 

SHRINKHEAD — A  large  riser  containing  a  sufficient  body  of 
metal  to  act  as  a  feeder  as  the  metal  of  the  casting  con- 
tracts in  solidifying. 

SHOT — Globules  of  metal  formed  in  the  body  of  a  casting,  and 
harder  than  the  remainder  of  it. 

SKELETON — A  metal  framework  on  which  a  flat  core  is  built. 

SKIM  CORES — Cores  set  in  skim  gates  to  act  as  skimmers. 

SKIM  GATE — A  sprue  so  arranged  as  to  skim  any  impurities 
from  the  surface  of  the  molten  iron  as  it  flows  into  the 
mold,  and  restrain  them  from  entering  the  mold. 

SKIN-DRIED  MOLD — A  green-sand  mold  whose  surface  has  been 
baked  for  a  depth  of  an  inch  or  more. 

SLAG — The  earthy  impurities  fused  in  the  melting  furnace,  to- 
gether with  the  fused  flux  charged  with  the  fuel  and  metal. 


296  GLOSSARY 

SLAG-HOLE — The  opening  in  a  cupola  through  which  slag  is 

withdrawn. 
SLICKER — An  elongated,   flat,   thin   piece  of  steel   used   for 

smoothing  the  surfaces  of  molds. 
SLIP — A  wash  applied  to  the  surface  of  loam  molds. 
SLURRY — The  mixture  used  to  fill  in  the  joints  of  cores. 
SLURRYING — The  process  of  filling  in  the  joints  of  cores. 
SNAP  FLASK — A  flask  hinged  at  the  corners,  and  separable  at 

one  corner,  so  that  it  may  be  opened  and  removed  from 

around  a  completed  mold. 
SOLDIER — A  wooden  stick  or  rod,  clay  washed;  used  to  support 

bodies  of  hanging  sand,  or  large  green-sand  cores. 
SPINDLE — The  rod  or  center  on  which  a  sweep  is  revolved. 
SPINDLE  SEAT — The  socket  in  which  the  spindle  revolves. 
SPLIT  PATTERN — A  pattern  made  in  two  or  more  parts. 
SPLIT-PATTERN     SQUEEZER  —  A     squeezer      type     molding 

machine,  either  hand  or    power,    adapted    to    molding 

split  patterns. 
SPOON  SLICKER — A  finishing  tool  for  a  mold,  the  end  of  which 

is  made  of  spoon  shape. 
SPRING  DRAW-NAIL — A  tool  for  drawing  patterns,  especially 

gear  patterns,  by  gripping  the  inside  of  the  hole  in  the  hub. 
SPRUE — The  channels  leading  from  the  gate  to  the  mold. 

Also,  the  metal  which  solidifies  in  these  channels  after  the 

casting  has  cooled. 
SPRUE  CUTTER — A  piece  of  metal,  used  to  cut  channels  in  the 

joint  to  conduct  iron  from  the  pouring  gate  to  the  mold. 

Also  a  brass  tube  used  to  cut  the  pouring  gates  in  the 

copes  of  machine-made  molds. 
STACK — The  portion  of  a  cupola  extending  from  the  top  of  the 

melting  zone  to  the  level  of  the  charging  door. 
STOOL — The  support  for  a  green-sand  core  on  a  molding 

machine. 
STOOLING — The  process  of  supporting  green-sand   cores  in 

machine  molding  while  the  pattern  is  being  drawn. 
STOOL  PLATE — The  plate  on  a  molding  machine  on  which 

stools  are  mounted. 


GLOSSARY  297 

STRICKLE — A  strike  with  a  form  cut  in  one  edge  to  form  a 

regular  surface  on  a  mold. 

STRIKE — A  flat  bar  of  iron  or  wood  used  for  striking  or  sweep- 
ing excess  sand  from  the  top  of  a  mold. 
STRIPPING  PLATE — A  plate  on  a  molding  machine  on  which  the 

mold  is  made  and  through  which  the  patterns  are  drawn 

from  the  mold. 

SWAB — A  Hmp  brush  made  of  teazled  hemp  rope  used  for  wet- 
ting molds  around  the  edges  of  patterns;  swabbing,  the 

action  of  applying  water  to  a  mold. 
SWEEP — A  piece  of  wood  or  iron  revolved  about  a  center  to 

form  the  surface  of  a  mold. 
SWEEP  FINGER — The  metal  piece  by  means  of  which   the 

sweep  is  attached  to  the  spindle. 
TAP-HOLE — The  opening  in  a  melting  furnace — cupola  or  air — 

through  which  molten  metal  is  withdrawn. 
TIGHT  FLASK — A  flask  with  a  rigid  framework — the  opposite 

of  snap  flask. 
TROWEL — A  molder's  tool  used  for  slicking  the  surface  of  a 

mold. 
TUYERES — The  openings  in  a  cupola  through  which  air  is 

blown. 
TUYERE  ZONE — The  portion  of  a  cupola  in  the  region  of  the 

tuyeres,  where  combustion  takes  place. 
UPSET — A  shallow  frame  set  over  a  flask  in  which  is  formed 

a  green-sand  match. 
VENT — A  small  hole  formed  in  a  mold  to  permit  the  escape  of 

gas  from  it. 

VENT-WIRE — A  wire  used  for  making  vents. 
VIBRATOR — A  device  for  rapping  patterns  by  compressed  air. 
VIBRATOR  FRAME — A  frame  in  which  patterns  are  mounted 

when  they  are  to  be  drawn  in  connection  with  a  vibrator. 
WHIRL  GATE — A  gate  or  sprue  arranged  to  introduce  metal 

into  a  mold  tangentially,  and  to  thereby  give  it  a  swirling 

motion. 
WIND-BOX — The  chamber  surrounding  a  cupola  through  which 

air  is  conducted  to  the  tuyeres. 


APPENDIX 

TABLE  XVIII. — CIRCUMFERENCES  AND  AREAS  OF  CIRCLES 


Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

I 

3.1416 

•7854 

3     A 

11.192 

9.9678 

6    Y± 

19.635 

30.680 

A 

3-3379 

.8866 

11.388 

10.321 

% 

20.028 

3I-9I9 

Yk 

3-5343 

.9940 

II-585 

10.680 

|J^ 

20.420 

33-I83 

A 

3.7306 

1.1075 

11.781 

11.045 

Y% 

20.813 

34-472 

M 

3.9270 

1.2272 

t! 

11.977 

11.416 

H 

2I.2O6 

35-785 

A 

4-1233 

1-3530 

y& 

12.174 

H-793 

% 

21.598 

37-122 

% 

4.3197 

1.4849 

if 

12.370 

12.177 

7 

21.991 

38.485 

A 

4.5160 

1.6230 

4 

12.566 

12.566 

22.384 

39-871 

Yi 

4.7124 

1.7671 

A 

12.763 

12.962 

M 

22.776 

41.282 

A 

4.9087 

I.9I75 

Y% 

12-959 

13-364 

N 

23.169 

42.718 

x^ 

5-1051 

2.0739 

A 

13-155 

13.772 

Yi 

23.562 

44.179 

H 

5.3014 

2.2365 

M 

13.352 

14.186 

H 

23-955 

45-664 

A: 

54978 

2.4053 

A 

13.548 

14.607 

H 

24-347 

47-173 

il 

5-694I 

2.5802 

« 

13-744 

15-033 

H 

24.740 

48.707 

J^ 

5-8905 

2.7612 

I3.94I 

15-466 

8 

25.133 

50.265 

if 

6.0868 

2.9483 

Yi 

H.I37 

15.904 

H 

25-525 

51.849 

2 

6.2832 

3-1416 

A 

14-334 

16.349 

H 

25.918 

53-456 

A 

6-4795 

3-3410 

§K' 

I4.530 

16.800 

26.311 

55.088 

8 

6-6759 

3-5466 

14.726 

I7.257 

H 

26.704 

56.745 

6.8722 

3.7583 

« 

H.923 

17.721 

N 

27.096 

58.426 

M 

7.0686 

3.976I 

}* 

15.119 

18.190 

H 

27.489 

60.132 

A 

7-2649 

4.2000 

I5.3I5 

18.665 

H 

27.882 

61.862 

% 

74613 

4-4301 

if 

I5.5I2 

19.147 

9 

28.274 

63.617 

A 

7-6576 

4.6664 

5 

15.708 

19-635 

28.667 

65-397 

Yi 

7.8540 

4.9087 

A 

I5-904 

20.129 

M 

29.060 

67.201 

A 

8.0503 

5-I572 

N 

16.101 

20.629 

% 

29-452 

69.029 

% 

8.2467 

5-4H9 

A 

16.297 

21.135 

Yi 

29.845 

70.882 

tt 

8.4430 

5.6727 

M 

16.493 

21.648 

H 

30.238 

72.760 

% 

8.6394 

5-9396 

A 

16.690 

22.166 

% 

30.631 

74.662 

if 

8.8357 

6.2126 

H 

16.886 

22.691 

H 

31.023 

76.589 

K 

9.0321 

6.4918 

A 

17.082 

23.221 

10 

31.416 

78.540 

if 

9.2284 

6.7771 

17.279 

23758 

M 

31.809 

80.516 

3 

9.4248 

7.0686 

A 

17-475 

24.301 

M 

32.201 

82.516 

A 

9.6211 

7.3662 

17.671 

24.850 

^i 

32-594 

84.541 

y% 

9.8I75 

7.6699 

17.868 

25-406 

Yi 

32.987 

86.590 

A 

10.014 

7.9798 

« 

18.064 

25-967 

5/s 

33-379 

88.664 

M 

10.210 

8.2958 

if 

18.261 

26.535 

¥ 

33-772 

90.763 

A 

10.407 

8.6179 

K 

18-457 

27.109 

34-I65 

92.886 

/% 

10.603 

8.9462 

if 

18.653 

27.688 

ii 

34-558 

95-033 

A 

10.799 

9.2806 

6 

18.850 

28.274 

% 

34-950 

97.205 

H 

10.996 

9.6211 

K 

19.242 

29.465 

M 

35-343 

99.402 

298 


APPENDIX 
TABLE  XVIII.— Continued 


299 


Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

H^ 

35-736 

IOI.62 

i?H 

54-978 

240.53 

23  5A 

74.220 

438.36 

H 

36.128 

103.87 

*f 

55-371 

243.98 

H 

74-6I3 

443-01 

5/Q 

36.521 

106.14 

M 

55-763 

247-45 

H 

75.006 

447.69 

% 

36.9H 

108.43 

% 

56.156 

250.95 

24 

75-398 

452-39 

V* 

37.306 

110.75 

18 

56.549 

254-47 

H 

75-791 

457-n 

12 

37-699 

II3-IO 

$ 

56.941 

258.02 

M 

76.184 

461.86 

YS 

38.092 

H5-47 

57-334 

261.59 

8 

76.576 

466.64 

H 

38.485 

117.86 

% 

57.727 

265.18 

i^ 

76.969 

471.44 

38.877 

I2O.28 

y 

58.119 

268.80 

% 

77.362 

476.26 

H 

39.270 

122.72 

5A 

58-512 

272.45 

H 

77-754 

481.11 

5/s 

39.663 

125.19 

X 

58.905 

276.12 

H 

78.147 

485.98 

H 

40.055 

127.68 

H 

59.298 

279.81 

25 

78.540 

490.87 

H 

40.448 

130.19 

19  , 

59.690 

283.53 

H 

78.933 

495-79 

13  i 

40.841 

132-73 

H 

60.083 

287.27 

H 

79-325 

500.74 

4L233 

135.30 

H 

60.476 

291.04 

% 

79.718 

505-71 

M 

41.626 

I37-89 

% 

60.868 

294-83 

Yi 

8o.ui 

510.71 

3/8 

42.019 

140.50 

H 

61.261 

298.65 

N 

80.503 

515-72 

N 

42.412 

I43-I4 

H 

61.654 

302.49 

% 

80.896 

520.77 

5/^ 

42.804 

145.80 

H 

62.046 

306.35 

% 

81.289 

525-84 

M 

43-197 

148.49 

H 

62.439 

310.24 

26 

81.681 

530.93 

K 

43-590 

151.20 

20 

62.832 

314.16 

% 

82.074 

536.05 

14  i 

43.982 

153-94 

« 

63.225 

318.10 

M 

82.467 

54I-I9 

44-375 

156.70 

M 

63-617 

322.06 

N 

82.860 

546.35 

% 

44.768 

159.48 

H 

64.010 

326.05 

Yz 

83-252 

551-55 

'AA 

45.160 

162.30 

H 

64.403 

330.06 

K 

83-645 

556.76 

H 

45-553 

165-13 

l| 

64-795 

334-10 

y 

84.038 

562.00 

^ 

45.946 

167.99 

« 

65.188 

338-16 

K 

84.430 

567.27 

M 

46.338 

170.87 

K 

65-581 

342.25 

27 

84.823 

572.56 

K 

46.731 

173.78 

21 

65-973 

346.36 

H 

85.216 

577-87 

15 

47.124 

176.71 

N 

66.366 

350.50 

M 

85.608 

583-21 

H 

47-517 

179.67 

M 

66.759 

354-66 

3^ 

86.001 

588.57 

% 

47.909 

182.65 

8^ 

67.152 

358.84 

Yi 

86.394 

593.96 

% 

48.302 

185.66 

Yi 

67-544 

363-05 

5A 

86.786 

599-37 

X 

48.695 

188.69 

5/s 

67.937 

367.28 

X 

87.179 

604.81 

% 

49.087 

191-75 

H 

68.330 

371-54 

H 

87.572 

610.27 

H 

49.480 

I94.83 

ys 

68.722 

375-83 

28 

87-965 

6I5-75 

% 

49-873 

197-93 

22 

69.115 

380.13 

H 

88.357 

621.26 

16 

50-265 

201.06 

% 

69.508 

384.46 

M 

88.750 

626.80 

H 

50-658 

204.22 

/€ 

69.900 

388.82 

89-I43 

632.36 

Yt 

51-051 

207.39 

N 

70.293 

393-20 

Yi 

89.535 

637-94 

N 

51-444 

210.60 

« 

70.686 

397.61 

% 

89.928 

643-55 

H 

51-836 

213.82 

.  M 

71.079 

402.04 

/A: 

90.321 

649.18 

H 

52.229 

217.08 

H 

71.471 

406.49 

H 

90.713 

654-84 

% 

52.622 

220.35 

H 

71.864 

410.97 

29  v 

91.106 

660.52 

% 

53-014 

223.65 

23 

72.257 

415.48 

91.499 

666.23 

17  1 

53.407 

226.98 

H 

72-649 

420.00 

M 

91.892 

671.96 

53.800 

230.33 

M 

73.042 

424-56 

% 

92.284 

677.71 

M 

54-192 

233.71 

3^ 

73-435 

429.13 

H 

92.677 

683.49 

H 

54-585 

237-10 

^ 

73.827 

433-74 

H 

93-070 

689.30 

300 


APPENDIX 
TABLE  XVIII.— Continued 


Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

29^ 

93.462 

695.13 

35% 

112.705 

1010.8 

42 

I3I-947 

1385.4 

% 

93-855 

700.98 

36 

113.097 

1017.9  ; 

ys 

132.340 

1393-7 

30 

94.248 

706.86 

yS 

113.490 

1025.0 

M 

132.732 

1402.0 

94.640 

712.76 

a 

113.883 

1032.1 

y% 

I33-I25 

1410.3 

M 

95-033 

718.69 

H 

II4-275 

1039.2 

Yi 

133-518 

1418.6 

% 

95.426 

724.64 

Yi 

114.668 

1046.3 

5A 

133.910 

1427.0 

Yi 

95-8I9 

730.62 

5/s 

II5.06I 

1053-5 

y* 

I34-303 

H35-4 

5/£ 

96.211 

736.62 

H 

H5-454 

1060.7 

v* 

134.696 

1443-8 

M 

96.604 

742.64 

% 

115.846 

1068.0 

43 

135.088 

1452.2 

% 

96.997 

748.69 

37 

116.239 

1075.2 

ys 

I35-48I 

1460.7 

31 

97-389 

754-77 

H 

116.632 

1082.5 

& 

I35-874 

1469.1 

H 

97.782 

760.87 

M 

117.024 

1089.8 

y% 

136.267 

1477.6 

M 

98.175 

766.99 

y% 

117.417 

1097.1 

Yi 

136.659 

1486.2 

% 

98.567 

773-14 

K 

II7.8IO 

1104.5 

5/s 

137.052 

1494.7 

Yl 

98.960 

779-31 

5/8 

118.202 

iiu.8 

y 

137-445 

1503.3 

«fl 

99-353 

785-51 

H 

118.596 

1119.2 

ys 

137.837 

I5II-9 

M 

99.746 

791-73 

% 

118.988 

1126.7 

44 

138.230 

1520.5 

% 

100.138 

797.98 

38 

II9-38I 

1134.1 

H 

138.623 

1529.2 

32 

100.531 

804.25 

y8 

II9773 

1141.6 

M 

139-015 

1537-9 

H 

100.924 

810.54 

M 

I2O.I66 

1149.1 

*A 

139.408 

1546.6 

3 

101.316 

816.86 

y* 

120.559 

1156.6 

1A 

139.801 

1555-3 

y% 

101.709 

823.21 

1A 

120.951 

1164.2 

y% 

140.194 

1564.0 

Yi 

102.102 

829.58 

H 

121.344 

1171.7 

% 

140.586 

1572.8 

5/o 

102.494 

835-97 

M 

121.737 

1  1  79-3 

H 

140.979 

I58I.6 

% 

102.887 

842-39 

7/8 

122.129 

1186.9 

45 

141.372 

1590.4 

J^ 

103.280 

848.83 

39 

122.522 

1194.6 

ys 

141.764 

1599-3 

33 

103.673 

855-30 

H 

122.915 

1202.3 

i/ 

142.157 

1  60S.  2 

H 

104.065 

861.79 

123.308 

I2IO.O 

% 

H2.550 

I6I7.O 

M 

104.458 

868.31 

y% 

123.700 

I2I7.7 

Yi 

142.942 

I626.O 

104.851 

874.85 

y* 

124.093 

12254 

W 

143-335 

1634.9 

Yi 

105.243 

881.41 

y* 

124.486 

1233.2 

M 

143.728 

I643.9 

% 

105.636 

888.00 

*A 

124.878 

I24I.O 

H 

I44-I2I 

1652.9 

M 

106.029 

894.62 

% 

125.271 

1248.8 

46 

I44-5I3 

1661.9 

% 

106.421 

901.26 

40 

125.664 

1256.6  \   H 

144.906 

1670.9 

34 

106.814 

907.92 

ys 

126.056 

1264.5 

M 

145-299 

1  680.0 

107.207 

914.61 

1A 

126.449 

1272.4 

% 

145.691 

1689.1 

M 

IO7.6OO 

921.32 

126.842 

1280.3 

Yi.  146.084 

1698.2 

% 

107.992 

928.06 

/^ 

127.235 

1288.2 

y%  146.477 

1707.4 

H 

108.385 

934.82 

H 

127.627 

1296.2 

M  !  146.869 

I7I6.5 

5/g 

108.778 

941.61 

M 

I28.O2O 

1304.2 

y% 

147.262 

I725-7 

M 

109.170 

948.42 

% 

128.413 

1312.2 

47  . 

I47-655 

1734-9 

K 

109.563 

955-25 

41 

128.805 

1320.3 

1A 

148.048 

1744.2 

35 

109.956 

962.11 

H 

129.198 

1328.3 

M 

148.440 

1753-5 

110.348 

969.00 

M 

129.591 

1336-4 

y% 

148.833 

1762.7 

M 

II0.74I 

975-91 

H 

129.983 

1344-5 

Yt. 

149.226 

I772.I 

s 

III.I34 
III.527 

982.84 
989.80 

II 

130.376 
130.769 

1352.7 
1360.8 

% 

149.618 
I50.0II 

I78I.4 
1790.8 

% 

III.9I9 

996.78 

M 

I3I.I6I 

1369-0 

7/s 

150.404 

iSOO.I 

2 

II2-3I2 

1003.8 

K 

131-554 

1377.2 

48 

150.796 

1809.6 

APPENDIX 
TABLE  XVIII.— Continued 


301 


Diam. 

Circum. 

Area. 

Diam 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

48  Ys 

151.189 

1819.0 

54  ¥ 

170.431 

23II-5 

60^ 

189.674 

2862.9 

H 

151-582 

1828.5 

170.824 

2322.1 

190.066 

2874.8 

Ys 

I5I-975 

I837.9 

y& 

171.217 

2332.8 

!Hs 

190.459 

2886.6 

152.367 

1847.5 

Ys 

171.609 

2343-5 

M 

190.852 

2898.6 

Ys 

152.760 

1857.0 

H 

172.002 

2354-3 

Ys 

191.244 

2910.5 

M 

153-153 

1866.5 

K 

172.395 

2365.0 

61 

191.637 

2922.5 

7/s 

153-545 

1876.1 

55 

172.788 

2375-8 

y* 

192.030 

2934-5 

49 

I53-938 

1885.7 

173.180 

2386.6 

192.423 

2946.5 

I54-33I 

I895-4 

M 

173-573 

2397-5 

Ys 

192.815 

2958.5 

M 

I54-723 

1905.0 

% 

173.966 

2408.3 

y<i 

193.208 

2970.6 

/o 

I55-II6 

1914.7 

y^ 

I74.358 

2419.2 

% 

193.601 

2982.7 

^ 

I55-509 

1924.4 

Ys 

I7475I 

2430.1 

M 

193-993 

2994.8 

Ys 

I55-902 

1934-2 

M 

I75-I44 

2441.1 

Ys 

194.386 

3006.9 

% 

156.294 

1943-9 

H 

I75-536 

2452.0 

62 

194.779 

30I9.I 

Ys 

156.687 

1953-7 

56 

175.929 

2463.0 

^i 

I95-I7I 

303I-3 

50 

157.080 

1963.5 

ys 

176.322 

2474.0 

M 

I95-564 

3043-5 

157-472 

1973-3 

M 

176.715 

2485.0 

% 

195-957 

3055-7 

M 

157.865 

1983.2 

Ys 

177.107 

2496.1 

y& 

196.350 

3068.0 

^ 

158.258 

I993-I 

1A 

177.500 

2507.2 

Ys 

196.742 

3080.3 

^ 

158.650 

2003.0 

Ys 

177.893 

2518.3 

M 

197-135 

3092.6 

H 

159.043 

2012.9 

M 

178.285 

25294 

H 

197.528 

3104.9 

M 

159-436 

2022.8 

7A 

178.678 

2540.6 

63 

197.920 

3117.2 

% 

159.829 
160.221 

2032.8 
2042.8 

57  i 

179.071 
179.463 

2551.8 
2563.0 

198.313 
198.706 

3129.6 
3142.0 

51  H 

160.614 

2052.8 

/€ 

179.856 

2574-2 

iHj 

199.098 

3I54-5 

161.007 

2062.9 

Ys 

180.249 

25854 

/^ 

I9949I 

3166.9 

iHi 

161.399 

2073.0 

y* 

180.642 

2596.7 

5  / 

199.884 

3I79-4 

Yt 

161.792 

2083.1 

Ys 

181.034 

2608.0 

M 

200.277 

3I9I-9 

% 

162.185 

2093.2 

M 

181.427 

2619.4 

Ys 

200.669 

3204.4 

% 

162.577 

2103.3 

Vs 

181.820 

2630.7 

64 

2OI.O62 

32I7-0 

7A 

162.970 

2II3-5 

58 

182.212 

2642.1 

y* 

201.455 

3229.6 

52  i 

163.363 

2123.7 

K  i  182.605 

2653.5 

M 

201.847 

3242.2 

163.756 

2133-9 

y± 

182.998 

2664.9 

% 

202.240 

3254.8 

M 

164.148 

2144.2 

Ys 

183.390 

2676.4 

Y& 

202.633 

3267.5 

% 

164.541 

2154-5 

183-783 

2687.8 

Ys 

203.025 

3280.1 

H 

164.934 

2164.8 

% 

184.176 

2699.3 

203.418 

3292.8 

% 

165.326 

2I75.I 

M 

184.569 

2710.9 

JA 

203.811 

3305-6 

/4 

I657I9 

2185.4 

1/s 

184.961 

2722.4 

65 

204.204 

3318.3 

K 

I66.II2 

2195.8 

59 

I85.354 

2734.0 

H 

204.596 

333I-I 

53 

166.504 

22O6.2 

185747 

2745-6 

M 

204.989 

3343-9 

166.897 

2216.6 

M 

186.139 

2757-2 

205.382 

3356-7 

M 

167.290 

2227.O 

% 

186.532 

2768.8 

i/£ 

205.774 

H 

167.683 

2237-5 

Yi 

186.925 

2780.5 

Ys 

206.167 

3382.4 

i^ 

168.075 

2248.0 

% 

187.317 

2792.2 

M 

206.560 

3395-3 

H 

168.468 

2258.5 

M 

187.710 

2803.9 

Ys 

206.952 

3408.2 

M 

168.861 

2269.1 

H 

188.103 

2815.7 

66 

207.345 

3421.2 

K 

169.253 

2279.6 

60 

188.496 

2827.4 

^8 

207.738 

3434-2 

54 

169.646 

229O.2 

1A 

188.888 

2839.2 

M 

208.131 

3447-2 

170.039 

2300.8 

M 

189.281 

2851.0 

Ys 

208.523 

3460.2 

j 

302 


APPENDIX 
TABLE  XVIII.— Continued 


Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

66  Y2 

208.916 

3473-2 

72^ 

228.158 

4H2.5 

78  *A 

247.400 

4870.7 

y% 

209.309 

3486.3 

H 

228.551 

4156.8 

% 

247-793 

4886.2 

u 

209.701 

3499-4 

n 

228.944 

4I7I.I 

79 

248.186 

4901.7 

7A 

210.094 

3512-5 

73  ,, 

229.336 

4185.4 

H 

248.579 

4917.2 

67 

210.487 

3525-7 

K 

229.729 

4199.7 

% 

248.971 

4932.7 

210.879 

3538-8 

M 

230.122 

4214.1 

H 

249.364 

4948.3 

/4 

211.272 

3552-0 

% 

230.5H 

4228.5 

X 

249-757 

4963.9 

% 

211.665 

3565.2 

Yi 

230.907 

4242.9 

% 

250.149 

4979-5 

Yi 

212.058 

3578-5 

H 

231.300 

42574 

H 

250.542 

4995-2 

% 

212.450 

3591-7 

*A 

231.692 

4271.8 

7A 

250.935 

5010.9 

% 

212.843 

3605.0 

H 

232.085 

4286.3 

80 

251.327 

5026.5 

7A 

213.236 

3618.3 

74 

232.478 

4300.8 

ys 

251.720 

5042.3 

68 

213.628 

3631-7 

ys 

232.871 

43I5-4 

Y± 

252.113 

5058.0 

ys 

214.021 

3645-0 

M 

233.263 

4329-9 

% 

252.506 

5073-8 

M 

214.414 

3658-4 

%  233.656 

4344-5 

Yi 

252.898 

5089.6 

% 

214.806 

3671-8 

g 

234-049 

4359-2 

« 

253-29I 

5105-4 

% 

215.199 

3685-3 

y* 

234.441 

4373-8 

M 

253-684 

5121.2 

5A 

2I5-592 

3698.7 

H 

234-834 

4388.5 

% 

254.076 

5I37.I 

H 

215.984 

3712.2 

7A 

235-227 

4403.1 

81 

254.469 

5153.0 

7/8 

216.377 

3725-7 

75 

235-619 

44I7-9 

H 

254.862 

5168.9 

69 

216.770 

3739-3 

236.012 

4432-6 

M 

255-254 

5184.9 

y*  217.163 

3752.8 

M 

236.405 

4447-4 

% 

255-647 

5200.8 

M  1  217.555 

3766.4 

% 

236.798 

4462.2 

/4 

256.040 

5216.8 

y* 

217.948 

3780.0 

Yi 

237.190 

4477-0 

5A 

256.433 

5232-8 

1A 

218.341 

3793-7 

ys 

237-583 

4491.8 

H 

256.825 

5248.9 

y* 

218.733 

3807.3 

H 

237-976 

4506.7 

7A 

257.218 

5264.9 

ZA 

219.126 

3821.0 

7/s 

238.368 

4521.5 

82 

257.611 

5281.0 

H 

219.519 

3834.7 

76 

238.761 

4536.5 

1A 

258.003 

5297.1 

70 

219.911 

3848.5 

X 

239-I54 

4551-4 

H 

258.396 

5313-3 

ys 

220.304 

3862.2 

M 

239.546 

4566.4 

3A 

258.789 

5329.4 

¥ 

220.697 

3876.0 

H 

239-939 

458i.3 

H 

259.181 

5345-6 

22I.O9O 

3889.8 

Yi 

240.332 

4596.3 

« 

259-574 

536i.8 

Yi 

221.482 

3903.6 

5/s 

240.725 

4611.4 

M 

259-967 

5378.1 

5A 

221.875 

39I7-5 

241.117 

4626.4 

JA 

260.359 

5394-3 

¥ 

222.268 

3931-4 

JA 

241.510 

4641.5 

83 

260.752 

5410.6 

222.66O 

3945-3 

77 

241.903 

4656.6 

ys 

261.145 

5426.9 

7-i 

223.053 

3959-2 

ys 

242-295 

4671.8 

H 

261.538 

5443-3 

ys 

223.446 

3973-1 

1A 

242.688 

4686.9 

SA 

261.930 

5459-6 

M 

223.838 

3987-I 

% 

243.081 

4702.1 

H 

262.323 

5476.0 

% 

224.231 

4001.1 

% 

243-473 

47I7-3 

5A 

262.716 

5492.4 

% 

224.624 

4015-2 

y% 

243.866 

4732.5 

3A 

263.108 

5508.8 

ys 

225.017 

4029.2 

% 

244.259 

4747-8 

7A 

263.501 

5525-3 

H 

225.409 

4043-3 

y* 

244.652 

4763-I 

84 

263.894 

5541-8 

7/s 

225.802 

4057-4 

78 

245.044 

4778.4 

X 

264.286 

5558.3 

72 

226.195 

407I-5 

ys 

245-437 

4793-7 

¥ 

264.679 

5574-8 

H 

226.587 

4085.7 

*A 

245.830 

4809.0 

265.072 

5591-4 

M 

226.980 

4099.8 

3A 

246.222 

4824.4 

% 

265.465 

5607.9 

iMi 

227.373 

4114.0 

Yi. 

246.615 

4839.8 

H 

265.857 

5624-5 

K2 

227.765 

4128.2 

ys 

247.008 

4855.2 

M 

266.250 

5641.2 

APPENDIX 
TABLE  XVIII.— Continued 


303 


Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

Diam. 

Circum. 

Area. 

84  H 

266.643 

5657.8 

90 

282.743 

6361.7 

95  H 

298.844 

7106.9 

85 

267.035 

5674.5 

H 

283.136 

6379-4 

M 

299.237 

7125.6 

Hi 

267.428 

5691.2 

X 

283.529 

6397.I 

% 

299.629 

7H4.3 

M 

267.821 

5707-9 

« 

283.921 

6414.9 

Yi 

3OO.O22 

7163.0 

3A 

268.213 

5724-7 

« 

284.314 

6432.6 

H 

300.415 

7181.8 

1A 

268.606 

5741-5 

5/o 

284.707 

6450.4 

H 

300.807 

72OO.6 

% 

268.999 

5758.3 

% 

285.100 

6468.2 

ys 

3OI.2OO 

7219.4 

g 

269.392 

5775-1 

% 

285.492 

6486.0 

96 

301.593 

7238.2 

% 

269.784 

5791-9 

91 

285.885 

6503.9 

H 

301.986 

7257.I 

86 

270.177 

5808.8 

H 

286.278 

6521.8 

M 

302.378 

7276.0 

H 

270.570 

5825.7 

¥ 

286.670 

6539-7 

% 

302.771 

7294.9 

M 

270.962 

5842.6 

287.063 

6557-6 

1A 

303.164 

73I3.8 

3^ 

27I-355 

5859-6 

H 

287.456 

6575-5 

y* 

303.556 

7332.8 

y 

271.748 

5876.5 

5/s 

287.848 

6593-5 

H 

303-949 

7351-8 

N 

272.140 

5893.5 

%  \  288.241 

6611.5 

ys 

304-342 

7370.8 

% 

272.533 

5910.6 

Ji 

288.634 

6629.6 

97 

304-734 

7389.8 

^1 

272.926 

5927-6 

92 

289.027 

6647.6 

ys 

305.127 

7408.9 

s? 

273.319 

5944-7 

H 

289.419 

6665.7 

M 

305.520 

7428.0 

H 

273.7II 

5961.8 

H 

289.812 

6683.8 

305.913 

7447-1 

M 

274.104 

5978.9 

% 

290.205 

6701.9 

H 

306.305 

7466.2 

% 

274-497 

5996.0 

Yi 

290.597 

6720.1 

% 

306.698 

7485.3 

H 

274.889 

6013.2 

Y% 

290.990 

6738.2 

M 

307.091 

7504.5 

^8 

275.282 

6030.4 

M 

291.383 

6756.4 

% 

307.483 

7523-7 

M 

275.675 

6047.6 

jl 

291.775 

6774-7 

98 

307.876 

7543-0 

% 

276.067 

6064.9 

93    292.168 

6792.9 

H 

308.269 

7562.2 

88 

276.460 

6082.1 

292.561 

68II.2 

308.661 

7581.5 

H 

276.853 

6099.4 

M 

292.954 

6829.5 

3/g 

309.054 

7600.8 

M 

277.246 

6116.7 

% 

293.346 

6847.8 

Yi 

309.447 

7620.1 

% 

277.638 

6134-1 

Yi 

293-739 

6866.1 

H 

309.840 

7639-5 

i/£ 

278.031 

6151.4 

Y% 

294.132 

6884.5 

N 

310.232 

7658.9 

N 

278.424 

6168.8 

M 

294.524 

6902.9 

8 

310.625 

7678.3 

M 

278.816 

6186.2 

jl 

294.917 

6921.3 

99  v 

3II.OI8 

7697.7 

K 

279.209 

6203.7 

94  j/ 

295.310 

6939-8 

3II.4IO 

7717.1 

89 

279.602 

622  i  .  r 

295.702 

6958.2 

M 

311.803 

7736.6 

H 

279.994 

6238.6 

M 

296.095 

6976.7 

3^ 

312.196 

7756.1 

M 

280.387 

6256.1 

^ 

296.488 

6995-3 

Yi 

312.588 

7775-6 

S 

280.780 

6273-7 

/^ 

296.881 

7013.8 

5/8 

312.981 

7795-2 

« 

281.173 

6291.2 

5^ 

297.273 

7032.4 

M 

3I3.374 

7814.8 

^8 

281.565 

6308.8 

3^ 

297.666 

7051.0 

% 

313-767 

7834-4 

M 

281.958 

6326.4 

J^ 

298.059 

7069.6 

100 

3H-I59 

7854.0 

H 

282.351 

6344.1 

95 

298.451 

7088.2 

304 


APPENDIX 


TABLE  XIX.— SPHERES 
(Some  errors  of  i  in  the  last  figure  only.) 


Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

% 

.00307 

.OOOO2 

2     % 

17.721 

7.0144 

6    3A 

127.68 

135-66 

.OI227 

.00013 

18.666 

7-5829 

l/£ 

132.73 

143-79 

-fo 

.02761 

.00043 

% 

I9.635 

8.1813 

137.89 

152.25 

% 

.04909 

.OOIO2 

1% 

20.629 

8.8103 

P 

H3-H 

161.03 

& 

.07670 

.OO2OO 

S/g 

21.648 

9.4708 

% 

148.49 

170.14 

T% 

.11045 

•00345 

« 

[22.691 

10.164 

7 

153-94 

179-59 

~*h 

•15033 

.00548 

H 

23.758 

10.889 

J^j 

159-49 

189.39 

M 

•19635 

.00818 

U 

24.850 

11.649 

M 

165.13 

199-53 

& 

•24851 

.01165 

7A 

[25.967 

12.443 

% 

170.87 

210.03 

i& 

.30680 

.01598 

if 

27.109 

13.272 

^2 

176.71 

220.89 

M 

•37123 

.02127 

3 

28.274 

I4-I37 

% 

182.66 

232.13 

/% 

•44179 

.02761 

A 

29-465 

15.039 

M 

188.69 

243-73 

H 

.51848 

•035II 

ys 

30.680 

15-979 

jl 

194.83 

25572 

A 

.60132 

•04385 

A 

31.919 

16-957 

8 

201.06 

268.08 

M 

.69028 

•05393 

M 

33.183 

17-974 

H 

207.39 

280.85 

^ 

.78540 

•06545 

34-472 

19.031 

M 

213.82 

294.01 

A 

•99403 

.09319 

iNI 

35-784 

20.129 

H 

220.36 

307.58 

A, 

1.2272 

.12783 

A 

37.122 

21.268 

y2 

226.98 

321.56 

H 

1.4849 

.17014 

H 

38.484 

22.449 

233.7I 

335-95 

A: 

1.7671 

.22089 

A 

39.872 

23-674 

M 

240.53 

350.77 

i* 

2.0739 

.28084 

N 

41.283 

24.942 

1/9, 

247-45 

366.02 

8 

•   2.4053 

•35077 

H 

42.719 

26.254 

9 

254-47 

381.70 

« 

2.7611 

•43143 

H 

44-179 

27.611 

261.59 

397.83 

I 

3.1416 

.52360 

H 

45-664 

29.016 

M 

268.81 

414.41 

A 

3.5466 

.62804 

% 

47-173 

30.466 

iHj 

270.12 

431-44 

H 

3.9761 

•74551 

if 

48.708 

31.965 

Vz 

283.53 

448.92 

A 

4.4301 

.87681 

4 

50.265 

33-510 

5/s 

291.04 

466.87 

M 

4.9088 

1.0227 

H 

53-456 

36.751 

H 

289.65 

485-31 

1% 

54II9 

1.1839 

M 

56-745 

40.195 

% 

306.36 

504.21 

g 

5-9396 

1.3611 

60.133 

43.847 

10 

314.16 

523.60 

6.4919 

-5553 

Yi 

63.617 

47.713 

Ji 

322.06 

543-48 

i/£ 

7.0686 

.7671 

X 

67.201 

51.801 

^ 

330.06 

563-86 

A 

7.6699 

•9974 

H 

70.883 

56.116 

*/s 

338,16 

584.74 

% 

8-2957 

2.2468 

H 

74.663 

60.663 

1A 

346.36 

606.13 

tt 

8.9461 

2.5161 

5 

78.540 

65.450 

5/s 

354-66 

628.04 

A 

9.6211 

2.8062 

82.516 

70.482 

H 

363-05 

650.46 

II 

10.321 

3-II77 

M 

86.591 

75-767 

% 

371-54 

67342 

ji 

11.044 

3-45H 

^1 

90.763 

81.308 

ii 

380.13 

696.91 

i$ 

H-793 

3.8083 

^2 

95-033 

87.113 

H 

388.83 

720.95 

2 

12.566 

4.1888 

% 

99.401 

93-I89 

g 

397.61 

745-51 

A 

13-364 

4-5939 

% 

103.87 

99-541 

406.49 

770.64 

8 

14.186 

5-0243 

% 

108.44 

106.18 

Yi 

415.48 

796.33 

A 

15-033 

5.4809 

6 

113.10 

113.10 

% 

424.50 

822.58 

M 

15.904 

5-9641 

H 

117.87 

120.31 

% 

433-73 

849.40 

A 

16.800 

6-4751 

u 

122.72 

127-83 

* 

443-01 

876.79 

APPENDIX 
TABLE  XIX.— Continued 


305 


Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

12 

452.39 

904.78 

24  M 

1847.5 

7466.7 

38  K 

4656.7 

>988o 

H 

471.44 

962.52 

*i 

1885.8 

7700.1 

39 

4778.4 

31059 

% 

490.87 

1022.7 

M 

1924.4 

7938.3 

H 

4901.7 

32270 

H 

510.71 

1085.3 

25 

1963.5 

8181.3 

40 

5026.5 

33510 

13  1 

530.93 

II50.3 

M 

2OO2.9 

8429.2 

^ 

5I53.I 

34783 

551-55 

I2I8.0 

^ 

2042.8 

8682.0 

41 

528I.I 

36087 

Yi 

572.55 

1288.3 

% 

2083.0 

8939-9 

1A 

5410.7 

37423 

ZA 

593-95 

1361.2 

26 

2123.7 

92O2.8 

42 

5541-9 

38792 

14 

615.75 

1436.8 

H 

2164.7 

9470.8 

H 

5674-5 

40194 

\/ 

637-95 

I5I5.I 

22O6.2 

9744.0 

43 

5808.8 

41630 

% 

660.52 

1596.3 

% 

2248.0 

IOO22 

1A 

5944-7 

43099 

% 

683.49 

1680.3 

27 

2290.2 

10306 

44 

6082.1 

44602 

«5 

706.85 

1767.2 

X 

2332.8 

10595 

H 

6221.2 

46141 

730-63 

1857.0 

H 

2375-8 

10889 

45 

6361.7 

47713 

/^ 

754-77 

1949.8 

M 

2419.2 

IllSg 

1A 

6503-9 

49321 

M 

779.32 

2045.7 

28 

2463.0 

II494 

46 

6647.6 

50965 

16 

804.25 

2144.7 

M 

2507.2 

II805 

1A 

6792.9 

52645 

Ji 

829.57 

2246.8 

y* 

2551-8 

I2I2I 

47 

6939-9 

54362 

H 

855-29 

2352.1 

H 

2596.7 

12443 

^ 

7088.3 

56115 

M 

881.42 

2460.6 

29 

2642.1 

12770 

48 

7238.3 

57906 

17 

907.93 

25724 

M 

2687.8 

I3I03 

H 

7389-9 

59734 

M 

934-83 

2687.6 

H 

2734.0 

13442 

49 

7543-1 

61601 

962.12 

2806.2 

M 

2780.5 

13787 

X 

7696.7 

63506 

M 

989.80 

2928.2 

30 

2827.4 

I4I37 

50 

7854.0 

65450 

18 

1017.9 

3053.6 

M 

2874.8 

14494 

H 

8011.8 

67433 

M 

1046.4 

3182.6 

1A 

2922.5 

14856 

51 

8171.2 

69456 

Yi 

1075.2 

33I5.3 

H 

2970.6 

15224 

1A 

8332.3 

71519 

% 

1104.5 

3451-5 

31 

3019.1 

15599 

52 

8494.8 

73622 

19 

1134.1 

3591-4 

K 

3068.0 

15979 

H 

8658.9 

75767 

M 

1164.2 

3735-0 

|l 

3II7-3 

16366 

53 

8824.8 

77952 

H 

1194.6 

3882.5 

M 

3166.9 

16758 

H 

8992.0 

80178 

M 

1225.4 

4033-7 

32 

3217.0 

I7I57 

54 

9160.8 

82448 

20 

1256.7 

4188.8 

M 

3267.4 

17563 

K 

9331-2 

84760 

M 

1288.3 

4347-8 

H 

3318.3 

17974 

55 

9503-2 

87114 

Yz 

1320.3 

4510.9 

M 

3369-6 

18392 

H 

9676.8 

89511 

% 

1352.7 

4677-9 

33 

3421.2 

I88I7 

56 

9852.0 

91953 

21 

1385-5 

4849.1 

M 

3473-3 

19248 

N 

10029 

94438 

M 

1418.6 

5024.3 

H 

3525-7 

19685 

57 

10207 

96967 

H 

1452.2 

5203.7 

ZA 

3578-5 

2OI29 

H 

10387 

99541 

M 

1486.2 

53874 

34 

3631-7 

20580 

58 

10568 

102161 

22 

1520.5 

5575-3 

M 

3685-3 

21037 

^ 

10751 

104826 

K 

1555-3 

5767.6 

H 

3739-3 

2I50I 

59 

10936 

107536 

J4 

1590-4 

5964-1 

35 

3848-5 

22449 

H 

1  1  122 

110294 

M 

1626.0 

6165.2 

1A 

3959-2 

23425 

60 

II3IO 

113098 

23 

1661.9 

6370.6 

36 

407I-5 

24429 

« 

II499 

H5949 

K 

1698.2 

6580.6 

M 

4185-5 

25461 

6l 

II690 

118847 

^ 

1735-0 

6795-2 

37 

4300.9 

26522 

H 

II882 

121794 

M 

1772.1 

7014-3 

H 

4417.9 

27612 

62 

12076 

124789 

24 

1809.6 

7238.2 

38 

4536.5 

28731 

& 

12272 

127832 

306 


APPENDIX 
TABLE  XIX.— Continued 


Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

Diam. 

Surface. 

Volume. 

63 

12469 

130925 

751A 

17908 

225341 

88 

24328 

356819 

« 

12668 

134067 

76 

18146 

229848 

H 

24606 

362935 

64 

12868 

137259 

K 

18386 

234414 

89 

24885 

369122 

^ 

13070 

140501 

77 

18626 

239041 

H 

25165 

375378 

65 

13273 

H3794 

N 

18869 

243728 

90 

25447 

381704 

^ 

13478 

H7I38 

78 

I9II4 

248475 

ji 

25730 

388102 

66 

13685 

150533 

H 

19360 

253284 

91 

26016 

394570 

H 

13893 

153980 

79 

19607 

258155 

H 

26302 

40II09 

67 

14103 

157480 

H 

19856 

263088 

92 

26590 

407721 

y* 

I43H 

161032 

80 

2OIO6 

268083 

H 

26880 

414405 

68 

14527 

164637 

H 

20358 

273141 

93 

27172 

42Il6l 

^ 

14741 

168295 

81 

2O6I2 

278263 

H 

27464 

427991 

69,x 

14957 

172007 

H 

20867 

283447 

94 

27759 

434894 

H 

I5I75 

175774 

82 

2II24 

288696 

H 

28055 

441871 

70 

15394 

179595 

H 

21382 

294010 

95 

28353 

448920 

H 

I56I5 

I8347I 

83 

21642 

299388 

N 

28652 

456047 

7i 

15837 

187402 

H 

21904 

304831 

96 

28953 

463248 

H 

16061 

191389 

84 

22167 

310340 

H 

29255 

470524 

72 

16286 

195433 

H 

22432 

3I59I5 

97 

29559 

477874 

H 

16513 

199532 

85 

22698 

321556 

H 

29865 

485302 

73 

16742 

203689 

« 

22966 

327264 

98 

30172 

492808 

H 

16972 

207903 

86 

23235 

333039 

H 

30481 

500388 

74i, 

17204 

212175 

H 

23506 

338882 

99 

30791 

508047 

N 

17437 

216505 

87 

23779 

344792 

K 

3H03 

515785 

75 

17672 

220894 

H 

24053 

350771 

100 

31416 

523598 

1 

APPENDIX 


307 


TABLE  XX. — WEIGHT  AND  SPECIFIC  GRAVITY  OF  METALS 
(Kent's  "Mechanical  Engineers'  Pocket-Book,"  eighth  edition) 


Specific  Gravity, 
Range  According  to 
Several  Authorities 

Specific 
Gravity. 
Approximate 
Mean  Value 
Used  in 
Calculation 
of  Weight 

Weight 

cSSc 

Foot, 
Ibs. 

Weight 
per 
Cubic 
Inch, 
Ibs. 

Aluminum  

2.56    to    2.71 

2.67 

166.5 

o  0963 

Antimony 

6  66    to    6  86 

6  76 

4.21    6 

Bismuth 

974    to     Q  QO 

9  82 

612  4 

O   154.4. 

Brass:  Copper  +  Zincl 
80               20 
70               30  > 
60               40 

50               50  J 

(  Cop.,  95  to  80  ) 
Bronze  ]  ~ 
(  Tin,    5  to  20  ) 

Cadmium 

7.8      to    8.6 

8.52    to    8.96 
86      to    8  7 

f8.6o 
J    8.40 
I    8.36 
[  8.20 

8.853 

8  65 

536.3 
523.8 
521.3 
511.4 

552. 

C-5Q 

0.3103 
0.3031 
0.3017 
0.2959 

0.3195 

Calcium 

i   58 

i   58 

og    s 

o  0570 

Chromium  
Cobalt  
Gold,  pure  
Copper 

5-0 
8.5      to    8.6 
19.245  to  19.361 
8  69    to    8  92 

5-0 
8-55 
19.258 
8  851 

311.8 

533-1 
1200.9 

552 

0.1804 
0.3085 
0.6949 

Iridium  
Iron,  Cast  
Iron,  Wrought  
Lead 

22.38    to  23. 
6.85    to    7.48 
7-   4    to    7.9 
1  1  07    to  1  1  44 

22.38 
7.218 
7.70 
1  1  38 

1396. 

450. 
480. 

7OQ   7 

o  .  8076 
o  .  2604 
0.2779 

Manganese 

7          to    8 

8 

4.QO 

o  2887 

Magnesium  

r  32° 

Mercury                  -s    60° 

1  .  69    to    i  .  75 
13.60    to  13.62 

I  -i    eg 

i-75 
13.62 

I"?     eg 

109. 

849.3 
846  8 

0.0641 

0.4915 

Ul2° 

Nickel  

13-37  to  13.38 
8  279  to    8  93 

13-38 

8  8 

834-4 
548  7 

0.4828 

O   1175 

Platinum  

20  -33    to  22  07 

21  5 

1347  o 

o  7758 

Potassium  
Silver  .  .  . 

0.865 
10  474  to  10  511 

0.865 

IO    SOS 

53-9 
655  i 

0.0312 

O    17QI 

Sodium  
Steel  

0.97 
7.69*  to    7  932f 

0.97 

7  8S4 

60.5 
489  6 

0.0350 

o  28^4 

Tin 

7   2QI  to     7   4OQ 

4.58  i 

Titanium  . 

5-5 

5a 

•3-2Q     5 

O    IQI^ 

Tungsten  .... 

17          to  17  6 

17  ^ 

1078  7 

o  624^ 

Zinc  

6.86    to    7.20 

7.00 

436.5 

0.2526 

*  Hard  and  burned. 

less 


308 


APPENDIX 


TABLE  XXI. — MELTING-POINTS  OF  VARIOUS  SUBSTANCES 
(Kent's  "  Mechanical  Engineers'  Pocket-Book,"  eighth  edition) 

The  following  figures  are  given  by  Clark  (on  the  authority  of  Pouillet, 
Claudel,  and  Wilson),  except  those  marked  *,  which  are  given  by  Prof. 
Roberts-Austen,  and  those  marked  f,  which  are  given  by  Dr.  J.  A.  Harker. 
These  latter  are  probably  the  most  reliable  figures. 


Sulphurous  acid —  148°  F. 

Carbonic  acid —  108 

Mercury ~ 39,  —     38f 

Bromine -f-      9-5 

Turpentine 14 

Hyponitric  acid 16 

Ice 32 

Nitro-glycerine 45 

Tallow 92 

Phosphorus 112 

Acetic  acid 113 

Stearine 109  to  120 

Spermaceti 120 

Margaric  acid 131  to  140 

Potassium 136  to  144 

Wax 142  to  154 

Stearic  acid 158 

Sodium 194  to  208 

Iodine 225 

Sulphur 239 

Alloy,  iXtin,  t  iead.  .  .334,  367! 
Tin 446,449t 


Cadmium 442°  F. 

Bismuth 504  to  507 

Lead 618*,  62of 

Zinc 779*,  786f 

Antimony 1150,  1169 f 

Aluminum H57*,  1214! 

Magnesium 1200 

NaCl,  common  salt I472t 

Calcium Full  red  heat. 

Bronze 1692  ' 

Silver 1733*.  I75if 

Potassium  sulphate.  .  .1859*,  1958* 

Gold 1913*!  I947t 

Copper 1929*.  I943t 

Nickel 26oof 

Cast-iron,  white 1922,  2075! 

"       "     gray  2012  to  2786,  2228* 
Steel 2372  to  2532* 

"    hard 2570*;  mild,  2687 

Wrought-iron .  .2732  to  2912,  2737* 

Palladium 2732* 

Platinum 3227*,  3iiof 


APPENDIX 


309 


TABLE  XXII.— STRENGTH  OF  ROPES. 

(A.  S.  Newell  &  Co.,  Birkenhead.     Klein's  Translation  of  Weisbach, 
vol.  iii,  part  I,  sec.  2) 


HEMP 

IRON 

STEEL 

Tensile 
Strength, 
Gross  Tons 

Girth, 
Inches 

Weight 
per 
Fathom, 
Pounds 

Girth, 

Inches 

Weight 
per 
Fathom, 
Pounds 

Girth, 
Inches 

Weight 
per 
Fathom, 
Pounds 

*A 

2 

I 

I 

2 

1^ 

13^ 

I 

I 

3 

3% 

4 

!^8 

2 

4 

*/€ 

2^ 

34 

ij^ 

5 

41A 

5 

1% 

3 

6 

2 

3]^ 

i% 

2 

7 

5l/2 

7 

2^ 

4 

\y± 

2/^ 

8 

2M 

4!^ 

9 

6 

9 

2<Hi 

5 

i% 

3 

10 

2Mi 

5^ 

ii 

&A 

10 

2;H? 

6 

2 

3/^ 

12 

2M 

6J^ 

2^ 

4 

13 

7 

12 

2% 

7 

2J2 

4/^ 

H 

3 

7/^ 

15 

7^ 

14 

3H 

8 

2^ 

5 

16 

3/4 

8^2 

17 

8 

16 

33xg 

9 

2^2 

5/^ 

18 

3K 

10 

2% 

6 

20 

8*^ 

18 

35^ 

ii 

2% 

6J^ 

22 

3M 

12 

24 

9^ 

22 

3Ji 

13 

3x4 

8 

26 

10 

26 

4 

14 

28 

ii 

3° 

4/4 

15 

3^| 

9 

30 

4^ 

16 

32 

4J^ 

18 

3/^ 

10 

36 

12 

34 

4^ 

20 

3M      • 

12 

40 

3io 


APPENDIX 


TABLE  XXIII. — PITCH,  BREAKING,  PROOF,  AND  WORKING  STRAINS  OF 
CHAINS 

(Bradlee  &  Co.,  Philadelphia) 


,0 

D.  B.  G.  SPECIAL  CRANE 

CRANE 

a 

£ 

.s 

1 

1 

| 

ij 

a 

5 

5 

£ 

3 

V  S 

.0 

1 

£ 

S 

4-T 

fa 

So 

L 

ft 

u 

"S 

•S 

g 

V 

I 

is-o5 

1 

1 

1 

1 

S 

1 

Jl 

6 

1 

jj 

J35 

M 

ft 

% 

if 

1,932 

3,864 

I.2S8 

1,680 

3,360 

I,I2O 

A 

ft 

i 

iM 

2,898 

5,796 

1,932 

2,52O 

5,040 

1,  680 

X 

ft 

ij-i 

lA 

4,186 

8,372 

2,790 

3,640 

7,280 

2,420 

TS 

iA 

2 

i^ 

5,796 

11,592 

3,864 

5,040 

10,080 

3,360 

H 

ift 

2^i 

iH 

7,728 

15,456 

5,152 

6,720 

13,440 

4,487 

A 

ift 

3rV 

2 

9,660 

19,320 

6,440 

8,400 

16,800 

5,600 

X 

ift 

4rV 

2^ 

11,914 

23,828 

7,942;  10,360 

20,720 

6,900 

ft 

itt 
itt 

2A 

14,490 
17,388 

28,980 
34,776 

9,660!  12,600 
11,592  15,120 

25,200  8,400 
30,240  10,087 

ii 

21*8 

6yV 

2% 

20,286 

40,572 

13,524 

17,640 

35,280  11,760 

x 

2A 

8% 

2$ 

22,484 

44,968 

14,989 

20,440 

40,880 

13,620 

« 

aA 

9 

3& 

25,872 

51,744 

17,248 

23,520 

47,040 

15,680 

i 

2^2 

io>£ 

33/8 

29,568 

59,136 

19,712 

26,880 

53,760 

17,927 

iA 

2^8 

12 

sA 

33,264 

66,538 

22,176 

30,240 

60,480 

20,160 

iJi 

2M 

13^8 

3T$ 

37,576 

75,152 

25,050 

34,160 

68,320  22,770 

iA 

3A 

I3T7jr 

4 

41,888 

83,776  27,925 

38,080 

76,160  25,380 

3^ 

16 

46,200    92,400 

30,800 

42,000      84,000  28,003 

lA 

3  A 

IQK 

IA 

50,512  101,024 
55,748  111,496 

33,674 
37,165 

45,920     91,840  30,617 
50,680   101,360  33,780 

i  A 

3  16 

i9rV 

4^ 

60,368 

120,736 

40,245 

54,880 

109,760 

36,583 

iJ6 

3% 

23 

sH 

66,528 

133-056 

44,352 

60,480 

120,960 

40,327 

i  A 

4 

25 

5rV 

70,762 

141,524 

47,174 

65,520 

131,140 

43,187 

i% 

4% 

3i 

5K 

82,320 

164,640 

54,880 

2 

5% 

40 

6% 

107,520 

215,040 

71,680 

2M 

6% 

52% 

7% 

136,080 

272,160 

90,720 

2>i 

7 

64^ 

8^ 

168,000 

336,000 

112,000 

2% 

7% 

73 

9H 

193,088 

386,176 

128,725 

3 

7H 

86 

9K 

217,728 

435,456 

145,152 

The  distance  from  center  of  one  link  to  center  of  next  is  equal  to  the  inside  length  of  link, 
but  in  practice  3»B  in.  is  allowed  for  weld.  This  is  approximate,  and,  where  exactness  is  re- 
quired, chain  should  be  made  so. 

FOR  CHAIN  SHEAVES. — The  diameter,  if  possible,  should  be  not  less  than  thirty  times  the 
diameter  of  chain  used. 

EXAMPLE. — For  i-inch  chain  use  3o-inch  sheaves. 


APPENDIX 


TABLE  XXIV. — ANALYSES  OF  FIRE-CLAYS 
(Kent's  "Mechanical  Engineers'  Pocket-Book,"  eighth  edition) 


| 

<5 

_r 

<LJ 

q 

o 

. 

3 

1 

3 

Brand 

H 

in 

IS 

h 

? 

u 

4>O 

3 

^ 

£  &> 

Loss 

H 

i 

1"* 

oBB 

a 

| 

B 

I* 

1 

1 

I 

Mt.  Savage1  

50.46,35.90 

12.744     -50 

0.13 

O.O2 

TK 

ice 

1.65 

Mt.  Savage2 

I  .  15 

ciS  8n  in  08 

rn    en 

T2 

o 

in 

I    92 

Mt.  Savages  

I.  53  44-  40J33-  56  14.575;    -08 

Tr. 

O.  II 

0.247 

1-47 

Mt.  Savage*  

156.15  33.30 

9-68 

.59JO.  I?  O.  12 

0.88 

Strasburg,  O  

0.45  55.87 

41-39 

.60)0.4010.  30  o  .  29 

O.20 

2.79 

Cumberland,  Md  

i  .  15 

56.80 

30.08     7.69 

.67 

.  .    2  .  1O 

3.97 

Woodbridge,  N.  J  

67.84 

21.83    5-98 

-57 

0.28  0.242.24 

4-33 

Carter  Co.,  Ky  

68.01 

24  .  09    3  .  03 

.01 

3.01 

4.02 

Clearfield  Co.,  Pa  

48.35 

36.37  10.56 

.00 

0.07 

O.  12 

2. 

54 

4-73 

Clearfield6  and  

44.8O  1O.OO  TA.7O 

.30 

O.2Oil.OO 

Cambria  Cos.,  Pa.6.  . 

5I.SO 

44.85;    i.Od 

•  33 

0.23  i.  15 

Clinton  Co.,  Pa  
Clarion  Co.,  Pa  
Farrandsville,  Pa  

[.'46 

1.02 

63.1823.70      6.8? 

44.61  38.oiji3.63 
45.26  37.85  13.  3O 

.20 
.25 
•  03 

0.17  0.47 

0.080.41 

0.08  0.02 

2.52 
\'% 

4*55 
3-47 
3-59 

SOa'o'.ip 

0.20 

St.  Louis  Co.,  Mo  

67.47 

I9-33-IO.  4S 

.56 

0.41  O.O7 

I.C 

7 

5-  14 

Stourbridge   Eng 

73-82 

15-88 

6.45 

•  95 

Tr. 

Tr. 

O.9O 

3-85 

1  Mass.  Inst.  of  Technology,  1871.  2  Report  on  Clays  of  New  Jersey.  Prof.  G.  H.  Cook, 
1877.  3  Second  Geological  Survey  of  Penna.,  1878.  «  Dr.  Otto  Wuth  (2  samples),  1885. 
6  Flint  clay  from  Clearfield  and  Cambria  counties,  Pa.,  average  of  hundreds  of  analyses  by 
Harbison-Walker  Refractories  Co.,  Pittsburg,  Pa.  •  Same  material  calcined.  All  other 
analyses  from  catalogue  of  Stowe-Fuller  Co.,  1907. 


312 


APPENDIX 


TABLE  XXV.— SIZES  OF  FIRE-BRICK 


9-inch  straight 9  X  41A  X  2%  inches. 

Soap 9  X  2*4  Y.2% 

Checker 9X3  X3 

No.  i  Split 9  X4X  XiX 

No.  2  Split 9  X  4^2  X  2 


Jamb.  .  .  . 

No.  i  key. 

wide. 

No.  2  key. 


9  X  2%  thick  X  4K  to  4  inches. 

112  bricks  to  circle  12  feet  inside  diam. 

9  X  2K  thick  X  4K  to  3M  inches 


wide.     65  bricks  to  circle  6  ft.  inside  diam. 
No.  3  key. 

wide. 
No.  4  key . 

wide. 


9  X  2K  thick  X  4K  to  3  inches 

41  bricks  to  circle  3  ft.  inside  diam. 

9  X  2K  thick  X  4K  to  2%  inches 

26  bricks  to  circle  iK  ft.  inside  diam. 
No.  i  wedge  (or  bullhead) 9  X  4K  wide,  2  X  2^  to  2  in. 

thick,  tapering  lengthwise.     102  bricks  to  circle  5  ft.  inside 

diam. 
No.  2  wedge 9  X  41A  X  2K  to  iK  in.  thick. 

63  bricks  to  circle  2l/2  ft.  inside  diam. 
No.  i  arch 9   X  4K  X  2^  to  2  inches  thick, 

tapering  breadthwise.     72  bricks  to  circle  4  ft.  inside  diam. 
No.  2  arch 9  X  41A  X  2%  to  \%. 

42  bricks  to  circle  2  ft.  inside  diam. 

No.  i  skew 9  to  7  X  4K  to  2K- 

Bevel  on  one  end. 
No.  2  skew 9  X  2^  X  4K  to  2^. 

Equal  bevel  on  both  edges. 
No.  3  skew 9  X  2^  X  4K  to  iX- 

Taper  on  one  edge. 
24-inch  circle 8K  to  sH  X  4^  X  2K- 

Edges  curved,  9  bricks  line  a  24-inch  circle. 
36-inch  circle 8J<  to  6K  X  4X  X  2.54. 

13  bricks  line  a  36-inch  circle. 
48-inch  circle 8J<  to  ?J<  X  4K  X  2^. 

17  bricks  line  a  48-inch  circle. 

i3X-inch  straight I3K  X  2X  X  6. 

i3K-inch  key  No.  i 13^  X  2K  X  6  to  5  inch. 

90  bricks  turn  a  12-ft.  circle. 
i3X-inch  key  No.  2 13%  X  2^  X  6  to  4^  inch. 

52  bricks  turn  a  6-ft.  circle. 


Bridge  wall,  No.  i 

Bridge  wall,  No.  2 

Mill  tile 

Stoke-hole  tiles 

18-inch  block 

Flat  back 

Flat  back  arch 

22-inch  radius,  56  bricks  to  circle. 

Locomotive  tile 32  X  10  X  3- 

34  X  10  X  3- 

34  X  8     X  3- 

Tiles,  slabs,  and  blocks,  various  si 

30  in.  wide,  2  to  6  in.  thick. 


13  X  b%  X  6. 

13  X  6K   X  3- 

18,  20,  or  24  X  6  X  3- 

18,  20,  or  24  X  9  X  4. 

18  X  9  X  6. 

9  X  6  X  2K. 

9  X  6  X  3K  to  2#. 


36  X    8X3- 
40  X  10  X  3- 


12  to  30  in.  long,  8  to 


Cupola  brick,  4  and  6  in.  high,  4  and  6  in.  radial  width,  to  line  shells  23  to  66  in.  diameter. 

A  9-inch  straight  brick  weighs  7  Ib.  and  contains  100  cubic  inches.  (=  120  Ib.  per  cubic 
foot.  Specific  gravity  1.93.) 

One  cubic  foot  of  wall  requires  17  9-inch  bricks,  one  cubic  yard  requires  460.  Where 
keys,  wedges,  and  other  "shapes"  are  used,  add  10  per  cent  in  estimatingj  the  number 
required. 

One  ton  of  fire-clay  should  be  sufficient  to  lay  3,000  ordinary  bricks.  To  secure  the  best 
results,  fire-bricks  should  be  laid  in  the  same  clay  from  which  they  are  manufactured.  It 
should  be  used  as  a  thin  paste,  and  not  as  mortar.  The  thinner  the  joint  the  better  the  fur- 
nace wall.  In  ordering  bricks,  the  service  for  which  they  are  required  should  be  stated. 


APPENDIX 


313 


TABLE    XXVI. — NUMBER    OF    FIRE-BRICK    REQUIRED    FOR    VARIOUS 
CIRCLES 


Diam. 
of 
Circle 

KEY  BRICKS 

ARCH  BRICKS 

WEDGE  BRICKS 

* 
1 

I 

o 
2 

6 

S3 

1 

o 
£ 

0 

z 

1 

1 

I 

1 

JS 

1 

5. 

ft.   in. 

\ 

I   6 

25 

25 

1 

2   O 

17 

I  -I 

3O 

42 

42 

2   6 

1  / 

*o 
25 

ow 

•14 

31 

18 

49 

60 

60 

3   o 

^0 

38 

OT- 

38 

21 

36 

57 

48 

20 

68 

3   6 

32 

IO 

42 

10 

54 

64 

36 

40 

76 

4   o 

25 

21 

46 

72 

72 

24 

59 

83 

4   6 

19 

32 

51 

72 

8 

80 

12 

79 

91 

5   o 

13 

42 

55 

72 

15 

87 

98 

98 

5   6 

6 

53 

59 

72 

23 

95 

98 

8 

1  06 

6   o 

63 

63 

72 

30 

102 

98 

15 

113 

6   6 

58 

9 

67 

72 

38 

110 

98 

23 

121 

7   o 

52 

19 

7i 

72 

45 

117 

98 

30 

128 

7   6 

.... 

47 

29 

76 

72 

53 

125 

98 

38 

136 

8   o 

42 

38 

80 

.... 

72 

60 

132 

98 

46 

144 

8   6 

37 

47 

84 

72 

68 

140 

98 

53 

151 

9   ° 

31 

57 

88 

72 

75 

147 

98 

61 

159 

9   6 

.... 

26 

66 

92 

72 

83 

155 

98 

68 

1  66 

10   o 

21 

76 

97 

72 

90 

162 

98 

76 

174 

10   6 

16 

85 

101 

72 

98 

170 

98 

83 

181 

II   O 

II 

94 

105 

72 

105 

177 

98 

91 

189 

ii   6 

5 

104 

109 

72 

113 

185 

98 

98 

196 

12    O 

113 

113 

72 

121 

193 

98 

1  06 

204 

12    6 

117 

117 

For  larger  circles  than  12  feet  use  113  No.  I  Key  and  as  many  g-inch 
brick  as  may  be  needed  in  addition. 


314 


APPENDIX 


TABLE  XXVII.— WEIGHT  OF  CASTINGS  DETERMINED  FROM   WEIGHT 
OF  PATTERN 

(Rose's  "  Pattern-makers'  Assistant  ") 


WILL  WEIGH  WHEN  CAST  IN 

A  Pattern  Weighing  One 

Pound,  Made  of— 

Cast- 
iron. 

Zinc. 

Copper. 

Yellow 
Brass. 

Gun- 
metal. 

Ibs. 

Ibs. 

Ibs. 

Ibs. 

Ibs. 

Mahogany  —  Nassau  .  . 
Honduras 

10.7 
12.9 

10.4 
12.7 

12.8 

15-3 

12.2 
I4.6 

12.5 
15- 

Spanish.  . 

8-5 

8.2 

10.  I 

9-7 

99 

Pine,  red  

12.5 

12.  I 

14.9 

14.2 

14.6 

'     white  

16.7 

16.1 

19.8 

19.0 

19  5 

'     yellow  

14.1 

13-6 

16.7 

16.0 

16.5 

TABLE  XXVIII. — DIMENSIONS  OF  FOUNDRY  LADLES 


The  following  table  gives  the  dimensions,  inside  the  lining,  of  ladles  from 
25  Ibs.  to  1 6  tons  capacity.  All  the  ladles  are  supposed  to  have  straight 
sides.  (Am.  Mack.) 


Capacity 

Diam. 

Depth 

Capacity 

Diam. 

Depth 

Capacity 

Diam. 

Depth 

in. 

in. 

in. 

in. 

in. 

in. 

1  6  tons 

54 

56 

3  tons 

31 

32 

300  lb. 

11% 

IlH 

14     " 

52 

53 

2     " 

27 

28 

250  " 

10% 

II 

12      " 

49 

50 

ij^j  " 

24/^3 

25 

2OO   " 

IO 

ioj^ 

10     " 

46 

48 

i  ton 

22             22 

150    " 

9 

91A 

8    " 

43 

44 

X  " 

2O             2O 

100   " 

8 

8% 

6    " 

39 

40 

y*  " 

17 

17 

75  " 

7 

71A 

4    " 

34 

35 

1A  " 

131A 

13^2 

50  " 

(>1A 

&A 

APPENDIX 


315 


TABLE  XXIX. — COMPOSITION  OF  ALLOYS  IN  EVERY-DAY  USE  IN 
BRASS  FOUNDRIES 

(American  Machinist) 


Cop- 
per 

Zinc 

Tin 

Lead 

Admiralty  metal 
Bell  metal 

Ibs. 
87 

16 

Ibs. 
5 

Ibs. 
8 

4 

Ibs. 

For  parts  of  engines  on  board 
naval  vessels. 
Bells  for  ships  and  factories. 
For  plumbers,  ship  and  house 
brass  work. 
For  bearing  bushes  for  shafting. 
For  pumps  and  other  hydraulic 
purposes. 
Castings    subjected    to    steam 
pressure. 
For  heavy  bearings. 
Metal   from  which  bolts  and 
nuts  are  forged,  valve  spin- 
dles, etc. 
For  valves,  pumps,  and  general 
work. 
For    cog    and    worm    wheels, 
bushes,  axle  bearings,  slide 
valves,  etc. 
Flanges  for  copper  pipes. 
Solder  for  the  above  flanges. 

Brass  (yellow).  .  . 

Bush  metal  
Gun-metal  

Steam   metal  .  .  . 

Hard  gun-metal  . 
Muntz  metal  

Phosphor  bronze. 

Brazing  metal.  .  . 
14       solder... 

16 

64 
32 

20 

16 
60 

92 
90 

16 
50 

8 
8 

40 

3 
50 

4 
3 

iH 

2^ 

H 

4 
i 

8pho 

10   " 

s.  tin 

316 


APPENDIX 


TABLE  XXX.— USEFUL  ALLOYS  OF  COPPER,  TIN,  AND  ZINC 
(Selected  from  numerous  sources) 


Copper. 

Tin. 

Zinc. 

U.   Navy  Dept.  journal  boxes  )  _ 
and  guide-gibs  )  ~ 

I     6. 
1  82.8 
58.22 
62 
88 
|64 
187-7 
92-5 
9i 
87.75 
85 
83 

5  13 
I  76.5 
82 
83 

20 

87 

88 

84 
80 
81 
97 
89.5 
89 
89 
86 
85M 
80 
79 
74 
64 

I 

13-8 
2-30 

I 
10 

8 
II.  0 

5 
7 
9-75 

5 

2 

2 

ii.  8 
16 

15 

I 

4-4 
10 

H 

18 
17 

2 
2.1 

8 

2^ 
I2& 

18 
18 
9% 
3 

K  parts. 
3.4  percent. 
3948  " 
37 

2 
I    parts. 
i  .  3  per  cent. 

2-5    " 

2 

2-5      ' 
IO 

15          "       ' 

2   parts. 
11.7  percent. 
2  slightly  malleable. 
1.50  0.50  lead, 
i         i 
4-3     4-3 

2 

2 

2  o  antimony. 

Tobin  bronze  

Naval  brass  

Composition,  U.  S.  Navy  
Brass  bearings  (J.  Rose)  
Gun-metal 

ii        ii 

U        U 

Tough  brass  for  engines  
Bronze  for  rod-boxes  (Lafond) 

"    pieces  subject  to  shock.  . 
Red  brass            .                        parts 

Bronze  for  pump  casings  (Lafond)  . 
"    eccentric  straps     ' 
"    shrill  whistles  
"    low-toned  whistles  
Art  bronze,  dull  red  fracture. 

20          " 

5.6    2.  8  lead. 

i* 

2 
2 

2>£         yz  lead. 
93^       7       lead. 
29^       3^  lead. 

Gold  bronze    . 

Bearing  metal 

English  brass  of  A.D.  1504  

APPENDIX 


317 


TABLE  XXXI. — COMPOSITION  OF  VARIOUS  GRADES  OF  ROLLED 
BRASS,  ETC. 

(Kent's  "  Mechanical  Engineers'  Pocket-Book,"  eighth  edition) 


Trade  Name 

Copper 

Zinc 

Tin 

Lead 

Nickel 

6l    S 

-18   5 

60 

4-O 

66% 

T.T.I/. 

Low  brass 

80 

2O 

60 

4O 

\V> 

Drill  rod  

60 
6634 

40 

W1A 

\V<> 

1^4  to  2 



6iY* 

20\4 

18 

The  above  table  was  furnished  by  the  superintendent  of  a  mill  in  Connecticut  in  1894. 
He  says:  While  each  mill  has  its  own  proportions  for  various  mixtures,  depending  upon  the 
purposes  for  which  the  product  is  intended,  the  figures  given  are  about  the  average  standard. 
Thus,  between  cartridge  brass  with  33%  per  cent  zinc  and  common  high  brass  with  38^ 
per  cent  zinc,  there  are  any  number  of  different  mixtures  known  generally  as  "high  brass,"  or 
specifically  as  "spinning  brass,"  "drawing  brass,"  etc.,  wherein  the  amount  of  zinc  is 
dependent  upon  the  amount  of  scrap  used  in  the  mixture,  the  degree  of  working  to  which 
the  metal  is  to  be  subjected,  etc. 


TABLE  XXXII.— SHRINKAGE  OF  CASTINGS 
(Kent's  "  Mechanical  Engineers'  Pocket-Book,"  eighth  edition) 

The  allowance  necessary  for  shrinkage  varies  for  different  kinds  of  metal, 
and  the  different  conditions  under  which  they  are  cast.  For  castings  where 
the  thickness  runs  about  one  inch,  cast  under  ordinary  conditions,  the  fol- 
lowing allowance  can  be  made : 


For  cast-iron,  ^  inch  per  foot. 

"    brass,        tV    "      "      " 

"    steel,         14    " 

"    mal.  iron,  J/£    "      "      " 


For  zinc,  ^  inch  per  foot. 

"    tin,  rV   "      "      " 

"    aluminum,  rs   " 
"    britannia,    -53    "      "      " 


Thicker  castings,  under  the  same  conditions,  will  shrink  less,  and  thinner 
ones  more,  than  this  standard.  The  quality  of  the  material  and  the  man- 
ner of  molding  and  cooling  will  also  make  a  difference. 

Mr.  Keep  (Trans.  A.  S.  M.  E.,  vol.  xvi)  gives  the  following  "approxi- 
mate key  for  regulating  foundry  mixtures"  so  as  to  produce  a  shrinkage 
of  %  in.  per  ft.  in  castings  of  different  sections: 

Size  of  casting %         i  2          3          4        in.  sq. 

Silicon  required,  per  cent. ...   3.25     2.75     2.25     1.75     1.25     percent 
Shrinkage  of  a  >£-in.  test-bar  0.125  0.135  °-I45  o^SS  0-165  in.  per  ft. 


318 


APPENDIX 


TABLE    XXXIII.— SIZES  OF    PIPES  FOR  TUMBLING   BARRELS,  INCHES 
DIAMETER 

(Data  Sheet  of  The  Foundry,  Feb.,  1910) 


Diameter 

Length  of  Barrel,  Inches 

of 

Mill, 

Inches 

36 

48 

60 

72 

84 

24 

4 

4 

5 

6 

6 

30 

4 

4 

5 

6 

6 

36 

5 

5 

6 

6 

7 

42 

6 

6 

6 

7 

8 

48 

6 

6 

7 

8 

8 

TABLE  XXXIV.— DIAMETER  OF  EXHAUST  FAN  INLETS  FOR  TUMBLING 
BARRELS 

(Data  Sheet  of  The  Foundry,  Feb.,  1910) 


NUMBER  OF  MILLS 


Diameter 
of  Pipe 
to  Mill, 

Inlet  Diameter,  Inches 

Inches 

i 

2 

3 

4 

5 

6 

7 

8 

9 

IO 

4 

4*A 

f>y2 

&A 

8*A 

sy2 

10)4 

10)4 

12 

12 

12 

5 

51A 

VA 

VA 

10*4  \  12 

12 

H 

14 

16 

16 

6 

VA 

VA 

10)4 

12 

14 

14 

16 

18 

18 

20 

7 

VA 

10)4 

12 

14 

16 

18 

18 

20 

22 

24 

8 

sy2  \  12 

H 

16          18 

20 

22 

24 

24 

27 

1 

I 

APPENDIX 


319 


TABLE   XXXV. — STEEL    PRESSURE    BLOWERS   FOR  CUPOLAS    (AVERAGE 
APPLICATION) 

(American  Blower  Co.) 


1 

£ 
* 

a  a 
Q"" 

1 
£, 

f* 

•3d 

il 
££ 

u 

Dia.  Outlet, 
pipes,  in. 

3 

Oz. 

2 

3 

"Sd 
|* 

In. 

3.46 

5-19 

6.92 

8.65 

10.38 

12.  12 

13-83 

I5.56 

H.P. 

constant 
at  1000 
cu.  ft. 

1.242 

1.86 

2.48 

3-10 

3-73 

4-35 

4-95 

3915 
708 
3.51 

5.58 

U% 

1% 

3.80 

5% 

0.18 

R.P.M. 
C.F. 
H.P. 

1960 
361 
0.45 

2400 
434 
0.81 

2770 
500 
1.24 

3095 
560 
1-74 

3390 
610 

2.28 

3666 
665 
2.89 

4150 
752 
4.20 

17 

i% 

4-45 

6% 

0.2485 

R.P.M. 
C.F. 
H.P. 

1675 
498 
0.62 

2050 
600 

I.  12 

2362 
691 
1.72 

2645 
774 
2.40 

2895 
843 
3.15 

3130  3340 
9i6|  978 
3-99  4-84 

3540 
1038 
5-79 

19% 

1% 

| 

* 

2% 

5-  II 

7% 

0.327 

R.P.M. 
C.F. 
H.P. 

I460 
655 
0.82 

1785 
789 

1-47 

2060 

2300 

2520 

2730!  2910 

3085 
1365 
7.62 

2.26 

3.16 

4.15 

5-25 

6.36 

'__ 

24y2 


27 

5.76 

8% 

0.4176 

R.P.M. 
C.F. 
H.P. 

1292 
838 
1.04 

1582 
1006 
1.87 

1825 
1162 
2.88 

2040 
1300 
4-03 

2235 
1415 

5.28 

2420 
1540 
6.70 

2585 
1643 
8.14 

2740 
1746 
9-74 

6.41 

9% 

0.519 

R.P.M. 
C.F. 
H.P. 

Il62 

1040 
1.30 

1422 
1250 
2.33 

1640 
1442 
3-58 

1835 
1612 
5.00 

2OIO 
1760 

6.57 

2175 
1915 
8-34 

2320 
2040 

IO.  IO 

2460 
2166 

12.  IO 

7.06 

10% 

0.63 

R.P.M. 
C.F. 
H.P. 

1055 
1262 
1-57 

1290 
1520 
2.83 

1490 
1750 
4-34 

1665 
1960 
6.08 

1825 
?$ 

1975 
2375 

2105 

2475 

2233 

2630 
14.12 

32 

3% 

8.39 

i2y2 

0.852 

R.P.M. 
C.F. 
H.P. 

889 
1705 

2.12 

1087 
2055 
3-83 

231o 
5-86 

1405 
2650 
8.23 

1535 
2890 
10.78 

1660 
3140 
13.66 

1775 
3350 
16.60 

1880 

3555 
19.83 

37 

3% 

9.70 

14 

1.069 

R.P.M. 
C.F. 
H.P. 

769 
2140 

2.66 

940 

2575 
4-79 

1085 
2970 
7.36 

121 
332 
IO. 

1328 
3620 
13-5 

I446J  1533 
3940'  4200 
17.  15  20.00 

1625 
4460 
24.90 

42 

4% 

10.98 

16 

1.396 

R.P.M. 
C.F. 
H.P. 

679 
2800 
3-48 

830 
3370 
6.27 

958 
3880 
9-63 

107 

434 
13.46 

1172 
4730 
17.6s 

1270 
5150 
22.40 

1355 
5500 
27.25 

1435 
5825 
32.50 

47 

4% 

12.30 

I7V2 

1.67 

R.P.M. 
C.F. 
H.P. 

606 
3350 
4-17 

742 
4025 

7-5 

855 
4640 
II.  5 

956  1048 
5200  5660 

l6.  12  21  .  12 

1  133 
6160 
26.80 

I2IO 

657O 
32.55 

1280 
6970 
38.90 

52 

5% 

13-6 

I9V4 

2.  02 

R.P.M. 
C.F. 
H.P. 

548 
4050 
5-03 

670 

4870 
9.06 

774 
5610 
13.9 

865 
6290 
19-5 

947 
6850 
25-55 

1025 

7450 
32.40 

1093 
7950 
39-33 

1160 

8440 
47-10 

57 

5% 

14.92 

21 

2.405 

R.P.M. 
C.F. 
H.P. 

500   611 
4820  5800 
6.00  10.78 

70S 

6700 
16.62 

789    863 
7490   8l60 

23.2Sj30.45 

934 
8870 
38.60 

996 
4§485 

1056 
10040 
56.  10 

320 


APPENDIX 


TABLE    XXXVI. — STEEL  PRESSURE   BLOWERS    FOR    CUPOLAS  (AVERAGE 
APPLICATION) 

(Continued) 


1 

"8 

<r 

i, 
|s 

•3d 

0 

p 

Us 
Is 

.2  'a 
Q 

Area  of  Outlet, 
sq.  ft. 

Oz. 

IO     1      II 

12 

13 

14 

IS 

16 

In. 

17.28 

19.02 

20.75 

22.5 

24.22 

25-95 

27.66 

H.P. 

constant 
at  1000 
cu.  ft. 

6.20 

6.82 

7-44 

8.07 

8.69 

9-30 

9.92 

17 

i% 

4-45 

6% 

0.2485 

R.P.M. 
C.F. 
H.P. 

3740 
1093 

6.78 

3920 

"£ 

4090 
1196 

8.9 

I9V2 

i% 

S.n 

7% 

0.327 

R.P.M. 
C.F. 
H.P. 

3255 
1440 

8.93 

3415 
1510 

10.3 

3570 
1575 
11.72 

3710 
1642 
13.26 

3955 
1700 
14-75 

3985 
1762 
16.4 

4120 
1820 
18.05 

22 

2% 

5-76 

8% 

0.4176 

R.P.M. 
C.F. 
H.P. 

2890 
1840 
ii  .40 

3030 
930 
i    .16 

3163 

2OI2 
14.96 

3290 
2095 
16.9 

3420 
2175 
18.9 

3535 
2250 
20.9 

3650 
2325 
23.1 

24V2 

2% 

6.41 

9% 

0.519 

R.P.M. 
C.F. 
H.P. 

2595 
2280 

14.13 

720 
395 
i    -33 

2845 
25OO 

18.6 

2960 
2605 
21.05 

3075 
2700 
23-45 

3180 
2800 
26.05 

3280 

2885 
28.66 

27 

2% 

7.06 

10% 

0.63 

R.P.M. 
C.F. 
H.P. 

2355 
2770 

17.18 

470 
910 
19.85 

2580 
3033 

22.6 

2685 
3165 
25-55 

2790 
3280 
28.50 

2885 
3395 
31-55 

2980 
3500 
34-7 

32 

3% 

8.39 

i2y2 

0.8C2 

R.P.M. 
C.F. 
H.P. 

1983 
3750 
23.25 

2080 
3930 
26.80 

2170 
41X0 

30.6 

2260 
4276 
34-5 

2345 
4430 
38.5 

2430 
4590 
42.7 

2510 
4730 

47- 

37 
42 

3% 
4% 

9.70 

14 

1.069 

R.P.M. 
C.F. 
H.P. 

1715 

4700 
29.15 

1800 
4930 
33-66 

1880 
JI50 
.33 

1955 
536o 
43.25 

2030 
5560 
48.30 

2100 
5760 
53-55 

2170 
5940 
59- 

10.98 

16 

1.396 

R.P.M. 
C.F. 
H.P. 

1515 
6150 
38.15 

1590 
6450 
44.00 

1660 
6730 
50.15 

1728 
7010 
56.60 

1792 
7270 
63.2 

1855 
7525 
70. 

1916 

7760 
77- 

47 

52 

4% 

12.30 

I7V2 

1.67 

R.P.M. 
C.F. 
H.P. 

1352 
7350 
45.60 

1418 
7715 
52.66 

1480 
8055 
60.0 

1540 
8390 
67.66 

1600 
8700 
75-6 

1655 
9010 
83-9 

1710 
9300 
92.25 

5% 

13.6 

I9V4 

2.  O2 

R.P.M. 
C.F. 
H.P. 

1222 
8900 
55-20 

1282 
9330 
63.6 

1340 
9750 
72.5 

1393 
10140 
82.0 

1447 
10520 
91-5 

1498 
10890 

IOI.2 

1546 

II220 

III   33 

57 

5% 

14.92 

21 

2.405 

R.P.M. 
C.F. 
H.P. 

1113 
10580 

65.5 

1168 
IIIOO 

75.70 

I22O 
II60O 

86.33 

1270 
12080 
97-5 

1318 
12520 
109.0 

1363 
I296O 
120.5 

1410 
13380 
132.75 

APPENDIX 


321 


TABLE  XXXVII. — CAPACITY  OF  STURTEVANT  HIGH- PRESSURE  BLOWERS 


Number  of 
Blower 

C%Pef&e,USb.eet        ReVStneS  Per 

Inside  Diam. 
of  Inlet 
and  Outlet, 
Inches 

Approximate 
Weight, 
Pounds  * 

000 

i  to          5 

200  to  1000 

»H 

40 

00 

5  to        25 

375  to    800 

iH 

80 

O 

25  to        45 

370  to    800 

2^ 

140 

I 

45  to       130 

240  to    600 

3 

330 

2 

130  to      225 

300  to    500 

4 

550 

3 

225  to      325 

380  to    525 

4 

760 

4 

325  to       560 

350  to    565 

6 

1,  080 

5 

560  to    1  ,030 

300  to    475 

8 

1,670 

6 

1,030  to  vi,540 

290  to    415 

10 

2,500 

7 

i,  540  to    2,300 

280  to    410 

10 

3,200 

8 

2,300  to    3,300 

265  to    375 

12 

4,700 

9 

3,300  to    4,700 

250  to    350 

16 

6,100 

10 

4,700  to    6,006 

260  to    330 

16 

8,000 

ii 

6,000  to    8,500 

220  to    310 

20 

12,100 

12 

8,500  to  11,300 

190  to    250 

24 

18,700 

13 

1  1,  300  to  15,500 

190  to    260 

30 

22,700 

Of  blower  for  J^  Ib.  pressure. 


322 


APPENDIX 


TABLE  XXXVIII.— SPEED,  CAPACITIES,  AND   HORSE-POWER   OF 
SIROCCO  FANS 

(American  Blower  Co.) 

The  figures  given  represent  dynamic  pressures  in  oz.  per  sq.  in.     For  static  pressure, 
deduct  28.8  per  cent;  for  velocity  pressure,  deduct  71.2  per  cent. 


E8 
.2- 
C£ 

£ 

£ 

&. 

I 
Oz. 

1% 
Oz. 

a 

a 

2 

Oz. 

21/2 

Oz. 

<L 

in. 
6 

9 

12 

15 

18 

21 

Cu.  ft. 
R.P.M. 
B.H.P. 

155 
1.  145 
.0185 

22O 
I,6l5 
.052 

270 

1,980 
.095 

3io 
2,290 
•  147 

350 
2,560 
.205 

2« 
.270 

410 
3,025 

•34 

440 
3,230 
.42 

490 
3,616 
-58 

540 
3,960 
.76 

Cu.  ft. 
R.P.M. 
B.H.P. 

350 
762 

.042 

500 
I,O76 
.118 

880 
808 
.208 
1,380 
645 
.326 

610 
1,320 
.216 
i,  080 
990 
.381 

700 

1,524 

.333 

790 
1,700 
.463 

860 

1,866 
.610 

930 

2,020 

-77 

1,000 
2,152 
.95 

I,  IIO 

2,408 

1.32 

1,220 
2,640 

1-73 

Cu.  ft. 
R.P.M. 
B.H.P. 

625 
572 

.074 

1.250 
1.  145 
.588 

1,400 
1,280 
.82 

1,530 
1,400 
1.  08 
2,400 

1,120 
1.69 

1,650 
1,512 
1.36 

1,770 
1,615 
1.66 
2,760 
1,290 
2.61 

1,970 
1,  808 

2^1 

3,090 

1.444 
3-65 

2,170 
1,980 

3,390 
1,580 
4.8 

Cu.  ft. 
R.P.M. 
B.H.P. 

975 
456 
.US 

1,690 
790 
.600 

1,950 
912 
.923 

2,180 

1,020 
1.29 

2,590 
I,2io 
2.14 

Cu.  ft. 
R.P.M. 
B.H.P. 
Cu.  ft. 
R.P.M. 
B.H.P. 
Cu.  ft. 
R.P.M. 
B.H.P. 

1,410 
38i 
.167 

1,925 
326 
.227 

1,990 
538 
_.470 
2,710 
462 
.640 
~3i540 
404 
.832 

2,440 
660 
.862 
3.310 
565 
1.17 
4.340 
495 
1.53 

2,820 
762 
^.-33 
3,850 
652 
1.81 
5,000 
572 
2.35 

3,i6o 
850 
1.85 

3.450 

933 

2.43 

3,720 
1,010 

3.07 

3.980 
1,076 
3-75 

4-450 
1,204 
5-25 

4,880 

1,320 

6.9 

4,290 
730 
_2_lS3 
5,6oo 
640 
3-28 

4,700 
800 
_3_-33 
6,120 
700 
4_-32 
7,780 
622 
5.48 

5,070 
864 
4.18 
6,620 

756 

5.44 
8,400 
672 

6.90 

5,420 
924 

—Si!.1 
7,080 
807 
6.64 

6,060 
1,032 
7-15 

6,620 
1,130 

8.680 
990 

12.2 

24 

2,500 
286 
.296 

7,900 
904 
9-3 

27 

30 
36 
42 

Cu.  ft. 
R.P.M. 
B.H.P. 

3.175 
-  254 
_-J73 
3,910 
228 
_.46o 
5.650 
190 
.665 

4-490 
359 
1.05 

5.500 
440 
1-94 
6,770 
395 
2.40 
9.750 
330 
3-44 
13,300 
283 
4-69 

6,350 
508 
2.98 

7,100 
568 
4.16 

8,980 

.?S 

10,050 
804 
II.  8 

11,000 

"   880 
15-5 

Cu.  ft. 
R.P.M. 
B.H.P. 
Cu.  ft. 
R.P.M. 
B.H.P. 
Cu.  ft. 
R.P.M. 
B.H.P. 

5.520 
322 
_ll30 
7,950 
269 
1.8? 
10,850 
231 
2.55 

7,820 
456 
_3^68 
11,300 
38l 
5-30 

8,750 
510 
5-  IS 

9,600 
560 
6.  75 

10,350 

604 

8.53 

11,050 
645 
10.4 

12  ,350 
?22 

14-5 

13-550 
790 

19-500 
660 
.   2?.S 
26,600 
566 
37-5 

12,640 
425 

_L-4o 
17,170 
365 

IO.  I 

13,800 
466 
9-72 
18,800 
400 
13.3 

14,900 
504 

_I2_.25 
20,300 
432 
16.7 

15,900 
538 
-*L° 
21,700 
462 
20.4 

17,800 
602 

20.9 
24,250 
516 
28.5 

7.700 
163 
.903 

15,400 
326 

7.24 

48 
54 

Cu.  ft. 
R.P.M. 
B.H.P. 

10,000 

,31 

14.150 

202 
3-32 

.,17,350 
248 
6.10 

20,000 
286 
_9_i40 

25,400 
254 
II.  9 

22,400 
320 
13.1 

24,500 
350 
17.2 

26,500 

378 
21.75 

28,300 

2fi 

3I,6OO 
452 

37-1 

34,700 
$1 

Cu.  ft. 
R.P.M. 
B.H.P. 

12,700 
127 
1.49 

17,950 
179 

4.20 

22,000 
22O 

7.75 

28,400 
284 
16.6 

31,100 
311 

21.9 

33,600 
336 
27.6 

35,900 

359 
33-7 

40,200 
402 
47.1 

44,000 
440 
62. 

60 
66 

Cu.  ft. 
R.P.M. 
B.H.P. 
-CuTfT 
R.P.M. 
B.H.P. 

15,650 
114 
1.84 

22,100 

161 

5.20 
26,800 

147 
6.30 

27,100 
198 
9.58 

31.300 

228 

14-7 

35,000 
255 

20.6 

42,3"oo 
232 
24-9 

38,400 
280 
27.0 
46,400 
254 
32.7 

41,400 
302 
34.1 
50,100 
275 
41.2 

44,200 
322 
41.6 
53,600 
294 
50.4 

49,400 
36i 
58.2 

54,200 
396 
76.5 

18,950 
104 

2.23 

32,850 
1  80 
11.  6 

37,900 
208 
17-8 

60,000 
328 
70.4 

65,700 
360 
92.6 

72 
78 

Cu.  ft. 
R.P.M. 
B.H.P. 
Cu.  ft. 
R.P.M. 
B.H.P. 

22,6OO 
2^ 

Tf! 

30,800 

8  1 

3.61 

31,800 
134 
7.48 
37,350 
124 
8.77 

39.000 
165 
13.7 
45,800 
153 
16.1 

45,200 
190 

21.2 
52,800 
I?6 
24.8 

50,600 

212 
29.6 

55,200 
233 
_3L» 
64,700 

215 

45.6 

59,600 
252 
49.0 

63,600 
269 
59-8 

71,200 
301 
83.6 

78,000 
330 
no. 
91,600 
305 
129. 

59,100 
197 

34-7 

"70,000 
233 
57.5 

74,700 
248 

70.2 

83,500 
278 
98. 

84 
90 

Cu.  ft. 
R.P.M. 
B.H.P. 

43,400 
US 

IO.2 

53.200 
142 
18.7 

6l,6OO 
163 
28.9 

68,700 
182 
40.4 

75,200 

200 

53-0 

81,200 
216 
66.8 

86,800 

^ 

97,100 
258 
114. 

106,400 
283 
150. 

Cu.  ft. 
R.P.M. 
B.H.P. 

35,250 
76 
4.14 

49,800 
107 
ii.  7 

61,000 
132 
21.5 

70,500 
152 

33-1 

78,800 
170 
46.2 

86,400 

1  86 
60.7 

93,300 

2OI 
76.7 

99,600 
214 

93-6 

111,200 
241 
131- 

122,000 
264 
172. 

APPENDIX 


323 


TABLE  XXXIX.— CAPACITY  OF  ROTARY  BLOWERS  FOR  CUPOLAS 


Cu.  Ft. 
per 
Rev. 

Revs. 
per 
Min. 

Tons 
Hour 

Suitable 
for  Cupola 
In.  Diam.* 

Cu.  Ft. 
RPeCv. 

Revs. 
& 

Tons 
Hourr 

Suitable 
for  Cupola 
In.  Diam.* 

1-5 

j  200 

I  400 

I 
2 

>-  l8t020 

45 

(135 
ji65 

12 

15 

>  54  to  66 

3-3 

175 

1335 

I 
2 

j-  24  to  27 

(  200 
(  130 

18 
15 

) 

6 

(185 
(275 

2 
3 

!•  28  to  32 

57 

155 
(  185 

18 

21 

V  60  to  72 

10 

j  200 
(  250 

4 
5 

j-  32  to  38 

65 

(  HO 
«  160 

18 
21 

[  66  to  84 

!I50 

4 

(185 

24 

! 

13 

190 

5 

V  32  to  40 

125 

21 

175 

VA 

) 

84 

]>45 

24 

>  72  to  90 

(  150 

5 

) 

(  160 

27 

J 

17 

•j  2°5 

VA 

[•36  to  45 

SI2O 

24 

) 

(250 

sy2 

) 

IOO 

135 

27 

)-  84  to  96 

1  66 

8 

1  60 

30 

1 

24 

200 

10 

f  42  to  54 

(US 

27 

)  Two 

240 

12 

) 

118 

•j  130 

30 

V  cupolas 

ISO 

10 

(  140 

33 

)  60  to  66 

33 

1  80 

12 

48  to  60 

210 

H 

*  Inside  diam.     The  capacity  in  tons  per  hour  is  based  on  30,000  cu.  ft.  of  air  per  ton  of 
iron  melted. 


324 


APPENDIX 


TABLE  XL.— DIAMETERS  OF  BLAST  PIPES 
(B.  F.  Sturtevant  Co.) 


g 

c 

1 

1  = 

I 

ft 

ii 

u 

LENGTH  OF  PIPE  IN  FEET 

•  20 

40 

60 

80 

IOO        I2O        140 

DIAMETER  OF  PIPE  WITH  DROP  OF 

£ 

A 

5 

£ 

£ 

£' 

£ 

£ 

£ 

£ 

£ 

A 

9 

£ 

£ 

£ 

23 

500 

6 

7 

6 

7 

6 

8 

7 

9 

8 

8 

9 

8 

3 

4 
5 

6 

1 
9 
10 

II 

12 
13 
14 
15 

16 

17 

18 
19 

20 

21 
22 
23 
24 
25 

26 
27 

28 

29 
30 

30 

39 

42 
45 
48 
54 

60 
60 
66 

66 
66 

72 

72 

72 
78 

i 

84 
90 
90 
90 
90 

1,500 
2,000 
2,500 

3,000 

3,500 
4,000 
4,500 
5,000 

5.500 
6,000 
6,500 
7,000 
7,500 

8,000 
8,500 
9,000 
9,500 
10,000 

10,500 

11,000 

11,500 
12,000 
12,500 

13.000 
13,500 
14,000 
14.500 
15.  ooo 

10 

ii 

8 
9 

12 

ii 

13 
IS 

16 

17 
18 

12 

13 
14 

IS 
IS 

14 
IS 

17 
|2 

12 
14 

IS 

II 

11 

18 
18 

13 

14 

15 
16 
17 

IS 
17 

18 
19 
20 

14 
IS 

16 
17 
18 

17 
18 

20 
21 

12 

14 

IS 

16 
18 
18 

13 

13 
IS 
IS 
IS 

II 

12 
12 
13 
13 

IS 

11 

13 
13 

IS 

18 

IS 

19 

17 

20 

18 

21 

23 

20 

23 

20 

20 

11 
18 

18 
18 
18 

20 
2O 

21 
21 
21 
22 
22 

22 
23 
23 
23 

24 

14 
14 

11 

16 
16 

17 

11 

18 
18 
19 
19 
19 

19 
20 

20 

20 

21 

19 
20 

17 
18 

21 

22 

18 
19 

23 

23 

19 
20 

23 

24 

21 

3 

22 

26 

23 
23 

24 

24 

25 

26 
26 

26 

27 

11 

22 

18 

23 

20 

24 

22 

26 

22 

26 

23 

27 

22 
23 
23 

24 
24 
25 

11 

26 
26 
27 
27 

27 

2O 
2O 

21 
21 
21 

24 
25 

26 

27 

22 

22 

23 

23 

24 

26 

27 

27 

28 

28 

23 
23 

23 

24 
25 

28 
28 

29 

29 

30 

23 
24 

25 
26 
26 

28 

29 

30 

30 
30 

25 
25 

26 
27 

27 

29 

30 

30 

31 
31 

22 

22 
23 
23 

23 
24 

28 
28 

24 
24 

29 
29 

26 
26 

31 
31 

27 
27 

32 
32 

28 
28 

33 

33 
34 
34 
34 
35 

28 

28 

28 

29 

30 
30 

29 

29 
29 

1 

26 

30 

31 
31 

27 
27 

27 

32 
32 
32 

28 
28 
28 

33 
33 
34 

29 

29 

30 

INDEX 


ADMIRALTY  metal,  composition  of, 

3i5 
Air-furnace,  271,  288 

construction,  271 

fuel  for,  274 

operation,  271 
Alloys,  composition  of,  279,  315 

copper-tin-zinc-,  table  of,  316 
Aluminum  in  iron,  237 
Analyses  of  castings,  241 
Annealing,  228 
Arbor,  132,  288 

BARS,  288 
Basin,  288 

pouring,  294 
Bath,  288 
Bead-slicker,  288 
Bearing  metal,  316 
Bed  charge,  250,  288 
Bedding  patterns  in  foundry  floor, 

48 

Bellows,  211,  288 
Bench,  288 

work,  I,  288 
Binders,  56,  288 

core,  139 
Black  sand, 288 
Blacking,  charcoal,  232 

coke,  232 

Lehigh,  232 
Blast,  288 

pipes,  diameters  of,  324 
Blowers,  cupola,  capacities  of,  319, 
321,322 

rotary,  for  cupola,  capacities  of, 
323 


Bod,  255,  288 

Bosh,  211,  288 

Boshing,  5 

Bottom-board,  288 

Box,  set-off,  295 

Brackets  on  columns,  molding,  70 

Brass,  composition  of,  315,  317 

founding,  275 

red,  composition  of,  316 
Brazing    metal,     composition    of, 

315 

solder,  315 
Break-out,  288 
Breast  of  cupola,  250,  289 
Bricks,  fire,  289 

loam,  124,  289 
Bronze,  composition  of,  316 
Brush,  289 
Buckle,  131,  289 
Bung,  289 

Bush  metal,  composition  of,  315 
Butt,  289 

CALIPERS,  216,  289 
Camber,  68 

Camel's-hair  brush,  289 
Carbon,  combined,  234 

graphitic,  235 

in  iron.  234 

temper,  235 

Carrying  plate,  118,  289 
Car-wheel,  molding,  84 
Car-wheels,  drop  test,  88 

thermal  test,  88 
Casting,  289 

malleable,  293 

shrinkage  of,  317 


325 


326 


INDEX 


Castings,  analyses  of  iron  for,  241 

burning  on,  204 

cleaning,  181 

determination      of    weight    of 
from  weight  of  pattern,  314 

mending  broken,  204 

straightening  crooked,  180 

treatment  of,  while  cooling,  176 
Cementite,  234,  289 
Center  of  loam  mold,  124 
Chains,  strength  of,  310 
Chaplet,  156,  289 

in  cylindrical  mold,  159 

in  quarter-turn  pipe  mold,  162 

use  of,  62 

use  of  in  column  molds,  72 
Charge,  289 

bed, 288 
Charging  a  cupola,  252 

door,  289 
Cheek,  289 
,  false,  291 

of  loam  mold,  123 

ring,  1 20. 

use  of,  20 
Chill,  84,  289 
Chilled  work,  289 
Chuck,  289 
Churning,  175,  289 
Cinders,  use  of  in  pit  molding,  50 
Circles,  area  and  circumference  of, 

298 
Clamp,  210,  290 

use  of,  33 

Clamping  bar,  212,  289 
Clay  for  bod,  255 

wash,  290 

worm,  63 

Cleaning  castings,  181 
Cold  shut,  107,  290 
Columns,  cores  for,  73 

fluted,  pattern  for,  74 

gating,  72 

molding,  65 


Columns,  round,  molding,  69 

shrinkage  allowance,  74 
Coke,  ratio  of,   to  iron  in  cupola 

charges,  263 
Cooling  of  castings,  176 
Cope,  3,  290 

ascertaining  proper  bearing  for, 
62,  68,  107 

down,  15,  18,  290 

plate,  1 19,  290 
Copper  in  iron,  237 
Copper-tin  zinc  alloys,  316 
Core,  290 

baked,  288 

barrel,  149 

barrel,  venting  of,  150 

binders,  139 

blacking  for,  154 

box,  138,  290 

cake,  148 

cover,  148 

dry-sand,  138 

for  columns,  73 

for  steel  castings,  137 

green,  292 

green,  making,  10 

green,  nailing,  10 

grids  in,  144 

hook,  286 

loam,  sweeping,  132 

locating,  17 

machines,  146 

ovens,  147 

pasting,  63 

plate,  142,  290 

print,  290 

rodding,  144 

sand  for,  138,  153 

setting,  156 
Cores,  skeleton  in,  144 

skim,  168 

tooth,  130 

venting,  63,  142 

wax  tapers  as  vents  in,  145 


327 


Core-driers,  103,  145,  291 
Corner  tool,  212,  290 
Crane,  284 

floor  work,  light,  43 
Cross,  124 
Crucible  furnace,  275 

tilting  furnace,  277 

zone,  259,  290 
Cupola,  290 

blast  pressure  for,  260 

building  breast  in,  250 

calculating  mixtures  for,  265, 
269 

charging,  248 

construction  of,  246 

fuel  for,  248 

igniting,  249 

lining,  repairs  of,  257 

operation  of,  245 

practice,  comparative,  table  of, 
262 

ratio  of  iron  to  fuel,  263 

relation   of  capacity   to   blast 
pressure,  263 

slagging,  254 
Cylinder,  molding  in  loam,  116 

DISK  crank,  cooling  of,  177 
Double-ender,  213,  290 
Draft,  290 
Drag,  3 

plate,  118 

Draw-bench     frame     molding     in 
flask,  56 

frame  molding  in  floor,  49 
Draw-nail,  290 

spring,  216,  296 
Draw-peg,  165,  290 
Draw-screw,  212,  291 
Draw-spike,  212,  291 
Dropping  bottom  of  cupola,  256 
Dry  sand,  291 

sand  cores,  138 

sand  mold,  100,  291 


Dry  sand  molds,  finishing,  102 

sand  molds,  mixtures  for,  100 
sand  molds,  repairing  breaks  in, 
102 

Driers,  core,  145,  291 

EARS,  291 

Engine  bed,  molding,  in  skin-dried 

mold,  91 
cylinder,  molding,  in  dry  sand, 

101 

Equipment,  foundry,  280 
Eye-bolt,  291 

FACING,  gas-house  carbon,  232 

material,  228 

Rhode  Island,  231 
False-cheek,  291 

use  of,  21 

Fans,  capacities  of,  319,  321,  322 
Feeding  head,  174,  291 
Ferrite,  234,  291 
Ferro-manganese,  236 
Fire-brick,  289 

number    required    for   various 
circles,  313 

sizes  of,  312 

Fire-clay,  analyses  of,  311 
Fire-sand,  233 
Fitting  up  snap  flask,  4 
Flange  tool,  213,  291 
Flask,  281,  291 

barred,  31 

sectional,  109 

snap, 296 

tight,  297 
Flat  back,  291 

back  pattern,  31 

gate,  291 
Floor  mold,  closing,  36 

mold,  pouring,  36 

molding,  30 

work,  i,  30,  297 
Flow-off,  56,  291 


328 


INDEX 


Flux,  291 

Fly-wheel,  molding,  in  loam,  128 

segment,  molding,  82 
Former  for  sheet-metal  work,  mold- 
ing, without  pattern,  82 
Foundry,  292 

equipment,  280 

ladles,  dimensions  of,  314 
Frozen  iron,  292 
Fuel  for  air-furnace,  274 
Furnace,  crucible,  275 

crucible  tilting,  277 

open-flame  oil,  277 

reverberatory,  294 

GAGGER,  33,  211,292 

board,  287 

use  of,  45 
Gap-press  frame,  molding,  in  floor, 

58 
Gate,  1 68,  292 

flat,  171,  291 

horn,  169,  292 

peg,  1 68, 294 

skim,  1 68,  294 

set,  1 68 

whirl,  172,  297 
Gate-cutter,  216 
Gate- pin,  213 

Gates,  location  of  in  barred  flask,  33 
Gate-stick,  292 
Gating,  292 

columns,  72 
Gear  molding,  25 

split,  molding,  28 
Gears,  bevel,  molding  on  floor,  39 
Graphite,  Ceylon,  230 
Green-sand  match,  17,  292 
Grid,  103,  129,  144,  292 

use  of,  92 
Gun  metal,  composition  of,  315,  316 

HAND  rammer,  use  of,  4 
squeezer,  185 


Hand  wheel,  molding,  17 
Hay  rope,  132,  292 
Head,  feeding,  291 

shrink,  295 
Heap  sand,  292 
Hearth,  292 

cupola,  259 
Heat,  292 
Horn  gate,  27,  292 
Hub  tool,  213,  293 
Hydrofluoric  acid,  182 

INGOT  mold,  287 

Iron,  cast,  shrinkage  of,  244 

composition  of,  234 

for  castings,  analyses  of,  241 

for  columns,  74 

for  frictional  wear,  244 

frozen,  292 

hard,  for  heavy  work,  243 

pig.     See  Pig  Iron 

rammer,  use  of,  32 

soft,  composition  of,  243 

JARRING  MACHINE,  194,  293 

shockless,  195 
Joint,  293 

making,  4 
Jolt  rammer,  194,  293 

KING,  experiments  of,  on  molding 
sand,  218 

LADLES,  foundry,  280 

foundry,  dimensions  of,  314 
Lathe-bed  legs,  molding,  30 
Lead,  Austrian,  231 

German,  231 

Mexican,  231 
Lifter,  212,  293 
Liquid  glass,  use  of,  38 
Loam,  293 

mixture,  120,  132 

mold,  293 


INDEX 


329 


Loam  mold,  breaking  open,  126 
molding,  116 

MACHINE  molding,  293 
Malleable  casting,  293 
Manganese  in  iron,  236 
Match  board,  163 

green-sand,  292 

plate,  165 

plates,  aluminum,  188 
Melting  points,  Table  of,  308 

rapidity  of,  260 

ratio,  252 

zone,  250,  259,  293 
Mending  broken  castings,  204 
Metals,  weight  and  specific  gravity 

of,  307 
Mixtures,    calculation   of,    for   the 

cupola,  265,  269 
Molasses  water,  101 
Mold,  293 

dry-sand,  IOO,  291 

face  of,  strengthened  by  rods, 
92 

finishing,  5 

floor,  closing,  36 

floor,  pouring,  36 

loam,  293 

skin-dried,  90,  295 

types  of,  I 

renting,  II 

weighting  of,  for  pouring,  8 
Mold-board,  293 
Molding  car-wheels,  84 

columns,  65 

cover  plate  with  sweep,  76 

cylinder  in  loam,  116 

double  groove  sheave  in  three- 
part  flask,  22 

draw-bench  frame  in  flask,  56 

draw-bench  frame  in  floor,  49 

engine  bed  in  skin-dried  mold, 
9i 

engine  cylinder  in  dry  sand,  101 


Molding  fly-wheel  in  loam,  128 

fly-wheel    segment     in     green 

sand,  82 
former    for  sheet- metal   work 

without  pattern,  82 
gap-press  frame  in  floor,  58 
gears,  25 

gears  on  the  floor,  39 
hand  wheel,  17 
in  three-part  flask,  20 
in    two-part    flask    with    false 

cheek,  21 

irregularly  shaped  patterns,  15 
lathe-bed  legs,  30 
loam,  116 
machine,  184,  293 
machine,  when  to  use,  202 
printing-press  cylinders  in  dry 

sand, 108 
pulleys,  37 
rectangular  block  in  snap  flask, 

3 

round  column,  69 
sand,  217,  293 
sand,  analyses  of,  220-222 
sand  for  steel  castings,  135 
sand,  tests  of,  225 
sand,  treatment  of,  226 
solid  shot,  23 
split  gears,  28 
tank  cover   plate   with  sweep, 

80 

tools,'  210 

type  cylinder  in  dry  sand,  112 
wire-cloth  loom  frame,  43 
with  sweep,  75 
Muntz  metal,  315 

NOWEL,  293 
OXY-ACETYLENE  welding,  208 

PARAFFINE  board,  189,  293 
Parting,  294 


330 


INDEX 


Parting  sand,  294 
Pattern,  294 

determining  weight  of  castings 
from,  314 

drawing,  5,  290 

drawing  with  the  crane,  47 

flat  back,  31 

gating  of,  292 

mounting,   in   vibrator  frame, 
189 

plate,   mounting  of  split  pat- 
terns on,  192 

sectional,  109 

split,  296 
Peen,  294 
Peg-gate,  294 
Permeability  of  sand,  218 
Phosphor-bronze,   composition    of, 

315 

Phosphorus  in  iron,  236 
Pickling,  182 
Pig  iron,  analyses  of,  238 

foundry,  specifications  for,  239 

grading  of,  237 
Pins,  294 

Pipe  tool,  213,  294 
Pit  molding,  48 

preparation  of  for  molding,  50 
Plate,  carrying,  289 

cooling  of,  178 

cope,  290 

stool,  296 

stripping,  297 
Plumbago,  230 
Print,  core,  290 

Printing-press  cylinders,  cooling  of, 
179 

cylinder?,  molding,  in  dry  sand, 

108 

Porosity  of  sand,  217 
Pouring-basin,  294      ' 
Pouring-box,  73 
Pulleys,  cooling  of,  178 

molding,  37 


Pumping,  175,  294 
Putty  worm,  no 

RAMMER,  210,  294 

iron,  use  of,  32 
Rapping,  294 

iron,  212,  216,  294 
Rattling,  181 
Riddle,  210,  295 
Riser,  174,  295 

for  steel  castings,  136 

location  of  in  barred  flask,  33 
Rods,  use  of,  to  strengthen  face  of 

mold,  92 

Roll-over  machine,  197,  295 
Roller,  286 

Ropes,  strength  of,  309 
Run-out,  295 
Runner,  56,  295 

box,  56 

S-HOOK,  286 
Sand,  black,  288 

green,  292 

heap,  292 

mixtures  for  dry-sand    molds, 
100 

molding,  217,  293 

parting,  294 
Scab,  131,  295 
Scaffolding,  256 
Scrap,  use  of  in  cupola,  266,  269 
Seacoal,  228 
Seating,  121 
Sectional  flask,  109 

pattern,   109 
Set-off  box,  34,  295 
Sheave,  double-groove,  molding  in 
three-part  flask,  22 

molding,  20 

Shockless  jarring  machine,  195 
Shot,  295 

molding  solid,  23 
Shovel,  210 


INDEX 


331 


Shrinkage,  174 

allowance  for  columns,  74 

of  cast-iron,  244 

table  of,  317 
Shrinkhead,  295 
Silicon  in  iron,  235 

loss  of  in  melting,  261 
Skeleton,  103,  129,  144,  295 

for  loam  mold,  127 

use  of,  92 
Skim  core,  295 

gate,  295 

Skin-dried  mold,  90,  295 
Slab  core,  use  of,  59 
Slag,  295 

hole,  256,  296 
Slagging  cupolas,  254 
Slicker,  212,  296 

bead, 288 
Sling,  284 
Slip,  121,  296 
Slurry,  143,  296 
Snap-flask,  296 

fitting  up  of,  4 

molding,  3 
Soapstone,  232 
Soldier,  211,  296 

use  of,  13 

Specific  gravity  of  metals,  307 
Spheres,  area  and  volume  of,  304 
Spiegeleisen,  236 
Spindle,  117,  296 

seat,  75,  117,  296 
Split  pattern,  296 

pattern  molding  machine,  190 

pattern,  molding  of,  8 

pattern  with  web  center,  mold- 
ing of,  12 
Spokes,  wrought-iron,  casting  in  hub 

and  rim  of  wheel,  38 
Spoon-slicker,  213,  296 
Spreader,  286 
Spring  draw- nail,  216,  296 
Sprue,  296 


Sprue  cutter,  216,  296 

cutter,  use  of,  7 
Squeezer,  hand,  292 

power,  185,  294 

split  pattern,  296 
Stack,  259,  296 
Staples,  286 
Starch,  use  of,  231 
Steam  metal,  315 
Steel  castings,  134 

castings,  cores  for,  137 

castings,  facing  for,  135 

castings,  fire-clay  for,  135 

castings,  molding  sand  for,  135 

castings,  risers  for,  136 
Stock  cores,  145 
Stool,  192,  296 

plate,  192,  296 
Stooling  of  patterns,  192 
Straight  edge,  287 
Strickle,  152,  297 
Strike,  210,  297 
Stripping  plate,  190,  297 
Sulphur,  absorption  of  by  iron,  260 

in  iron,  235 
Swab,  211,  297 

use  of,  5 
Sweep,  297 

finger,  76,  287,  297 

molding,  75 

molding  in  flask,  80 

use  of  in  column  molding,  68 
Sweeping  loam  mold,  120 

TALC,  232 

Tank   cover   plate,    molding,    with 

sweep,  80 
Tap  hole,  297 
Tapers,  wax,  in  cores,  145 
Thermit  welding,  207 
Time-study  of  hand  molding,  200 

of  machine  molding,  201 
Tin-zinc-copper  alloys,  316 
Titanium  in  iron,  237 


332 


INDEX 


Tobin  bronze,  composition  of,  316 

Transfer  plate,  192 

Trowel,  211,  297 

Trunnions,  loose,  286 

Tumbling- barrel,  181,  282 
sizes  of  pipe  for,  318 
exhaust  fan  inlets  for,  318 

Tuyere,  297 

zone,  259,  297 

Type  cylinder,  molding,  in  dry  sand, 


UPSET,  297 
use  of,  15 

VANADIUM  in  iron,  237 
Vent,  297 

wire,  211,  297 
Vibrator,  185,  297 

frame,  185,  297 


Vibrator      frame,    mounting  -  pat- 
terns in,  189 

WATER  pail,  210 
Weight  of  metals,  307 
Welding,  oxy-acetylene,  208 

thermit,  207 
Whirl  gate,  24,  297 
Wind  box,  297 

Wire-cloth  loom  frame,  molding,  43 
Wire,  vent,  297 
Worm,  clay,  63 

putty,  no 

YOKE,  284 

ZINC -tin-copper  alloys,  316 
Zone,  crucible,  259,  290 

melting,  250,  259,  293 

tuyere,  259,  297 


STATE  NORMAL  SCHOOL 

IM  ANGHLES,  CALIFORNIA, 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 

Los  Angeles 
This  book  is  DUE  on  the  last  date  stamped  below. 


SEP8 


LO.URO 


APR  1  1  1975 


Form  L9— Series  444 


UC  SOUTHERN  REGIONAL  LIBRARY  FACILITY 


A    000506131     2 


